Citroën ZR1 1997 1998, Z06 1997 1998, C4 1997 1998, C3 1997 1998, C2 1997 1998 User Manual

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ANTI-THEFT SYSTEM

Theft System

DESCRIPTION & OPERATION

WARNING: Deactivate air bag system before performing any service operation. See

AIR BAG RESTRAINT SYSTEM article. Do not apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.

UNIVERSAL THEFT DETERRENT (UTD) SYSTEM

The Universal Theft Deterrent (UTD) anti-theft system is designed to deter vehicle theft by pulsing horns and/or exterior lights when unauthorized vehicle entry is detected. The UTD is an internal function of BCM, utilizing PASS-Key(R), serial data and various switch inputs. PCM controls fuel enable circuit. BCM must exchange a unique password with PCM to allow fuel enable. If BCM detects an illegal intrusion, BCM will disable cranking and PCM will not enable fuel delivery. UTD system interacts with Remote Function Actuation (RFA). For more information on remote transmitter and RFA system, see KEYLESS ENTRY SYSTEM article.

System components include door ajar switches, hatch ajar switch, door lock cylinder switches, power lock switches, hood ajar switch (export only), key in ignition switch, BCM and relays.

PASS-KEY(R) SYSTEM

PASS-Key(R) system is designed to prevent vehicle theft. If incorrect key is used, steering column is not unlocked and engine's fuel system and starter are disabled. An ignition key with a specific electrical resistance must be used in ignition key lock cylinder. PASS-Key(R) system operates using sensing contacts which are located in ignition key lock cylinder. These contact a key resistor pellet which is located on the ignition key. When lock is rotated, battery voltage is applied through appropriate fuse to Body Control Module (BCM). Pellet resistance is then compared with programmed value in BCM non-volatile memory. There are 15 different resistances available. PASS-Key(R) system also disarms UTD system from armed or alarmed mode. If an invalid key is detected, system will disable fuel and cranking for 3 minutes. If a key is inserted or ignition switch is turned before 3 minutes has elapsed, timer will reset to 3 minutes. Disconnecting battery or removing fuses will not disable timer.

BCM controls steering column lock/unlock function. Ground is supplied by BCM through ignition switch to

revent locking with key in ignition. BCM monitors lock position to assure lock command has been accomplished. If BCM is unable to determine lock position, BCM will enter fail enable mode and prevent column lock operation and fuel enable. To clear fail enable mode, disconnect BCM fuse No. 25 for 15 seconds.

System components include ignition key, ignition key lock cylinder, electronic steering column lock module, theft deterrent relay, BCM and PCM.

COMPONENT LOCATIONS

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PASS-KEY(R) & UNIVERSAL THEFT DETERRENT SYSTEM COMPONENT LOCATIONS

Component Location

Body Control Module (BCM) Mounted Under Carpet, In Right

Footwell Clutch Pedal Position Switch Behind Clutch Pedal Fuel Door/Rear Compartment Lid Release Switch (Export

Only) Instrument Panel Electrical Center Mounted Under Carpet, In Right

Left & Right Door Ajar Indicator Switches In Door Latch Left & Right Door Control Modules Bottom Center Of Door Left & Right Door Key Switches Upper Rear Of Door Park/Neutral Position (PNP) Switch Left Side Of Transmission Powertrain Control Module (PCM) & Underhood Electrical

Center

In Engine Compartment, Near Battery

In Center Console

Footwell

PROGRAMMING

NOTE: BCM must be reprogrammed when an ignition key or BCM is replaced. A scan

tool must be used to perform programming procedure.

BCM/PASS-KEY(R)

NOTE: Performing following procedure will set DTC P1630. This is normal. After

procedure is completed, turn ignition off for 30 seconds. Turn ignition on. DTC P1630 should clear. If DTC does not clear, see TESTS W/CODES article in ENGINE PERFORMANCE section.

NOTE: Battery voltage must be maintained during procedure.

1. Connect scan tool. Turn ignition on. Select BCM RPO Programming. Program BCM with proper RPO codes. Go to next step.

2. Ensure proper communications between BCM and ECM. If communication to PCM does not exist, see TESTS W/CODES article in ENGINE PERFORMANCE section. If communication to BCM does not exist, see BODY CONTROL MODULE tool is available, go to step 4). If a scan tool is not available, go to next step.

3. Turn ignition on (engine off) for 11 minutes. Turn ignition off for 30 seconds. Turn ignition on (engine off) for 11 minutes. Turn ignition off for 30 seconds. Turn ignition on (engine off) for 11 minutes or until DTC P1630 sets. Turn ignition off for 30 seconds. Turn ignition on for 30 seconds. Start engine. If engine starts, go to BCM DIAGNOSTIC SYSTEM CHECK in BODY CONTROL MODULE article. If engine does not start, see TESTS W/CODES article in ENGINE PERFORMANCE section.

4. Connect scan tool to vehicle Diagnostic Link Connector (DLC). Turn ignition on. Using scan tool, enter SERVICE PROGRAMMING SYSTEM (SPS). After enterin

article. If a T50/T60(R) is available, go to step 5). If a scan

vehicle information, select Request Info

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soft key. Select DONE and follow instructions on Vehicle Set-Up screen. Disconnect scan tool from vehicle and connect to Techline terminal. Using Techline terminal, select SERVICE PROGRAMMING SYSTEM (SPS). Select terminal to scan tool programming method. Select DONE. Follow instructions on terminal. Select Vehicle Theft Re-Learn. Select Program at summary screen. Terminal will download information to scan tool. Disconnect scan tool from terminal and reconnect to vehicle DLC. Select SERVICE PROGRAMMING SYSTEM (SPS) from main menu. Enter vehicle model year and type information. Select Theft Re-Learn soft key. Follow instructions on scan tool. Security timer will remain on for about 11 minutes or until DTC P1630 sets. DO NOT disconnect scan tool during this time. When system is ready, turn ignition off for 30 seconds. Start engine. If engine starts, go to BCM DIAGNOSTIC SYSTEM CHECK in BODY CONTROL MODULE article. If engine does not start, see procedures in TESTS W/CODES article in ENGINE PERFORMANCE section.

5. Using T50/T60(R), enter SERVICE PROGRAMMING SYSTEM (SPS). Select terminal to vehicle programming. Select DONE and follow instructions on Vehicle Set-Up screen. Select Vehicle Theft Relearn. Follow instructions on terminal. Security timer will remain on for about 11 minutes or until DTC P1630 sets. DO NOT disconnect terminal during this time. When system is ready, turn ignition off for 30 seconds. Start engine. If engine starts, go to BCM DIAGNOSTIC SYSTEM CHECK in BODY CONTROL MODULE article. If engine does not start, see procedures in TESTS W/CODES article in ENGINE PERFORMANCE section.

REPLACING IGNITION KEY (SPARE KEY AVAILABLE)

NOTE: This procedure is to replace a lost or broken key when another correct key is

available.

Verifying Correct Key Code

Lost or broken keys must be replaced with a key that has proper resistance value. To determine resistance value or code, insert key into PASS-KEY(R) Interrogator (J 35628-A) and read key code. Use key blank matching this key code and cut it to match original key.

REPLACING IGNITION KEY (NO SPARE KEY AVAILABLE)

CAUTION: DO NOT disconnect Yellow 2-pin SIR connector when determining key

code.

NOTE: This procedure is to replace a lost or broken key when no spare key is

available.

Determining Mechanical Key Code

Determine code from code on ignition lock cylinder, recode or replace lock cylinder. Cut blank (no pellet) key to proper code for use in DETERMINING BCM PROGRAMMED KEY CODE steps.

Determining BCM Programed Key Code

To determine unknown BCM key code, use PASS-Key(R) Interrogator (J 35628-A) and Adapter (J 25628-A)

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and following procedure.

1. Remove knee bolster under steering column. Connect Adapter (J 35628-A) wiring to Yellow 3-pin PASSKey(R) dash connector at base of steering column. DO NOT connect to steering column wiring.

2. Turn on PASS-Key(R) Interrogator (J 35628-A) and move key code switch to "1" and attempt to start engine using blank key. If engine starts, key code is "1". If engine does not start, turn ignition off and press 4-minute timer on PASS-Key(R) Interrogator (J 35628-A).

3. When timer indicator light goes out, move key code switch to next number and attempt to start engine. If engine does not start, continue trying different key codes until proper key code is found.

FEATURE CUSTOMIZING

UTD functions may be customized to customer preference. Alarm mode can programmed to activate horn and lights (backup, turn signals, foglights) or horn only. System can be programmed to activate horn only, lights only or horn and lights when system is armed.

To program UTD system, turn ignition on. Press RESET button on Driver Information Center (DIC) until all warning messages are cleared from Instrument Panel Cluster (IPC) display. Press OPTIONS button until IPC displays LOCK & ARM. Press RESET button to choose UTD ARMING function. Options are HORN ONLY, LIGHTS ONLY, or HORN & LIGHTS. Press OPTIONS button again until IPC displays ALARM. Press RESET button to choose UTD ACTIVE function. Options are HORN or HORN & LIGHTS.

SYSTEM TESTING

UNIVERSAL THEFT DETERRENT (UTD) SYSTEM CHECK

Arming UTD System

1. Close all doors. Turn ignition on. If SECURITY indicator turns off when ignition is turned on, go to next step. If SECURITY indicator does not turn off when ignition is turned on, see procedures in SECURITY INDICATOR INOPERATIVE .

2. Turn ignition off. Remove key from ignition switch. Open left or right door. If SECURITY indicator flashes for 10 minutes, go to next step. If SECURITY indicator does not flash for 10 minutes, go to

SECURITY INDICATOR INOPERATIVE

3. Open left or right door. Use power door lock switch to lock doors. If SECURITY indicator remains on, go to next step. If SECURITY indicator does not remain on, go to SECURITY INDICATOR INOPERATIVE .

4. Repeat steps 1) and 2). Open left or right door. Use remote transmitter LOCK button to lock doors. If SECURITY indicator remains on, go to next step. If SECURITY indicator does not remain on, go to

REMOTE KEYLESS ENTRY

article.

5. Close all doors. If SECURITY indicator turns off after 10 seconds (system armed), go to next step. If SECURITY indicator does not turn off after 10 seconds (system not armed), go to SECURITY INDICATOR INOPERATIVE .

Activating UTD System

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To activate, use power door lock switch or inside lock lever to unlock door, use inside hatch release to open hatch, or open hood (export only). If alarm does not activate, go to THEFT DETERRENT SYSTEM

INOPERATIVE .

Disarming UTD System

1. Using key, unlock door. If alarm disarms, reset alarm and go to next step. If alarm does not disarm, go to

THEFT DETERRENT SYSTEM INOPERATIVE

2. Press UNLOCK button on remote transmitter. If alarm disarms, reset alarm and go to next step. If alarm does not disarm, go to KEYLESS ENTRY SYSTEM article.

3. Walk into range with passive transmitter (passive switch on). If alarm disarms, reset alarm and go to next step. If alarm does not disarm, go to KEYLESS ENTRY SYSTEM article.

4. Turn ignition on. If alarm disarms, reset alarm and go to next step. If alarm does not disarm, go to BODY CONTROL MODULE article.

5. Press hatch release button on remote transmitter. If alarm disarms, reset alarm and go to next step. If alarm does not disarm, go to KEYLESS ENTRY SYSTEM article.

SECURITY INDICATOR INOPERATIVE

NOTE: Use this test when indicator is always on, always flashing or never on.

1. Perform UNIVERSAL THEFT DETERRENT (UTD) SYSTEM CHECK . Using scan tool, check communications with BCM, LDCM, RDCM and PCM modules. If scan tool can communicate with all modules, go to next step. If scan tool is unable to communicate with module(s), see appropriate article for diagnosis and repair. After repair, turn ignition off. Reconnect all components and connectors. Turn ignition on. If repair is complete, see procedures in UNIVERSAL THEFT DETERRENT (UTD) SYSTEM CHECK .

2. Using scan tool, select IPC output functions and command SECURITY indicator ON and OFF. If indicator operates properly, go to next step. If indicator does not operate properly, see INSTRUMENT PANEL article.

3. Using power door lock switches, operate locks. If locks operate properly, go to next step. If locks do not operate properly, see appropriate KEYLESS ENTRY SYSTEM article.

4. Close both doors. Turn ignition on. If DOOR AJAR message is not displayed, go to next step. If DOOR AJAR message is displayed, see KEYLESS ENTRY SYSTEM

article.

5. Open driver door. If DOOR AJAR message is displayed, close door and open passenger door. If DOOR AJAR message is displayed, go to next step. If DOOR AJAR mesage is not displayed, see appropriate KEYLESS ENTRY SYSTEM article

6. Turn ignition on. If SECURITY indicator is off, go to next step. If SECURITY indicator is on or flashing, go to step 8).

7. Check following circuits for intermittent problems. Door ajar switches, power door lock switches, hood ajar switch (export only) and communications between BCM, RDCM, LDCM and PCM. If no problems are found, system is okay. If a problem is found, repair as necessary. Turn ignition off. Reconnect all components and connectors. Turn ignition on. If repair is complete, see UNIVERSAL THEFT DETERRENT (UTD) SYSTEM CHECK .

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8. Using scan tool, check for any UTD related DTCs. If any DTCs exist, see DIAGNOSTIC TESTS . If no

DTCs exist, system is okay.

THEFT DETERRENT SYSTEM INOPERATIVE

NOTE: Use this test when UTD system will not Arm or Disarm properly.

1. Perform UNIVERSAL THEFT DETERRENT (UTD) SYSTEM CHECK . Turn ignition off. Open driver or passenger door. Lock doors using power lock switch. Close doors. System should be armed. If system arms, go to next step. If system does not arm, go to step 5).

2. Disarm system, using key to unlock driver or passenger door lock. If system does not disarm, go to next step. If system disarms, go to step 6).

3. Disarm system, using UNLOCK button on remote transmitter or by walking into range (with passive switch on). If system does not disarm, go to next step. If system disarms, see KEYLESS ENTRY SYSTEM article.

4. Using scan tool, check communications with BCM, LDCM, RDCM and RFA modules. If scan tool can communicate with all modules, go to step 7). If scan tool is unable to communicate with module(s), see appropriate article for diagnosis and repair. After repair, turn ignition off. Reconnect all components and connectors. Turn ignition on. If repair is complete, system is okay.

5. Turn ignition off. Close doors. Press LOCK button on remote transmitter or walk out of range (with passive switch on). If system arms properly, see KEYLESS ENTRY SYSTEM article. If system does not Arm, go to step 4).

6. Check following circuits for intermittent problems. Door ajar switches, door lock cylinder switches, power door lock switches, hood ajar switch (export only) and communications between BCM, RDCM, LDCM and PCM. If no problems are found, system is okay. If a problem is found, repair as necessary. Turn ignition off. Reconnect all components and connectors. Turn ignition on. If repair is complete, go to UNIVERSAL THEFT DETERRENT (UTD) SYSTEM CHECK .

7. Replace BCM. Program new BCM. See PROGRAMMING .

UTD DATA DISPLAY INFORMATION

Scan tool displays UTD data. This information assists in determining if BCM is able to receive correct data to operate UTD system. This data is received from BCM. See UTD DATA Table.

UTD DATA

UTD Data Value (Volts)

Battery Volts 0-25.5 PASS-Key(R) Resistor Signal 0-5

UTD INPUT DISPLAY INFORMATION

Scan tool displays UTD input status. This information assists in determining if BCM is able to receive correct inputs to operate UTD system. This information is input from various sources and may be shared with other

stems. See UTD INPUT table.

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UTD INPUT

Input Value

Ignition 1 Ignition 2 Ignition 3 Key In Ignition Theft Deterrent State PASS-Key(R) State Driver Door Ajar Switch Passenger Door Ajar Switch Hood Ajar Switch Hatch/Trunk Ajar Switch Column Lock State Column Feedback Column Lock/Unlock "A" Column Lock/Unlock "B" Driver Door Lock/Unlock Switch

(1) (1) (1)

(1)

(1) (1)

(2)

Passenger Door Lock/Unlock Switch Driver Door Key Unlock Passenger Door Key Unlock Courtesy Switch Park Lamp Input

(1)

BCM input.

(4)

(2)

(3)

Active/Inactive Active/Inactive

Displayed Detection State

Active/Inactive Active/Inactive

Displayed Commanded Column Lock State

Active/Inactive Active/Inactive Active/Inactive Active/Inactive Active/Inactive Active/Inactive Active/Inactive

ON/OFF ON/OFF ON/OFF

ON/OFF ON/OFF

(2)

Left Door Control Module input.

(3)

Right Door Control Module input.

(4)

Instrument Panel Cluster input.

UTD OUTPUT DISPLAY INFORMATION

Scan tool can command some UTD output functions. This feature can be used to determine if UTD system is causing malfunction or if system responsible for controlling output is cause. Scan tool can energize selected system and display status of output. Display shown is command, not result. See UTD INPUT table.

UTD OUTPUT

Output Value

SECURITY Light

(1)

ON/Of

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Left Turn Signal Light Right Turn Signal Light Front Foglights Rear Foglights Backup Lights

(2)

Horn Column Lock "A" Column Lock "B"

(1)

IPC output.

(2)

BCM output.

(2) (2) (2)

(2) (2)

(2)

ON/OFF ON/OFF ON/OFF ON/OFF ON/OFF ON/OFF ON/OFF ON/OFF

STEERING COLUMN LOCK SYSTEM CHECK

1. Connect scan tool. Turn ignition on. Go to next step if steering column unlocks and scan tool displays the following BCM data:

z Steering Column Lock State - IGN ON UNLOCKED z Key In Ignition - ACTIVE z Key Out Of Ignition - ACTIVE (will not change) z Column Feedback - ACTIVE

If conditions are not met, go to STEERING COLUMN LOCK MALFUNCTION .

2. Turn ignition off (key in ignition switch). Go to next step if steering column remains unlocked and scan tool displays the following BCM data:

z Steering Column Lock State - IGN OFF UNLOCKED z Key In Ignition - ACTIVE z Key Out Of Ignition - ACTIVE (will not change) z Column Feedback - ACTIVE

If conditions are not met, go to STEERING COLUMN LOCK MALFUNCTION

3. Remove key from switch. Go to next step if steering column locks and scan tool displays the following BCM data:

z Steering Column Lock State - IGN OFF LOCKED z Key In Ignition - INACTIVE z Key Out Of Ignition - ACTIVE (will not change) z Column Feedback - INACTIVE

If conditions are not met, go to STEERING COLUMN LOCK MALFUNCTION .

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4. Insert key in ignition. Go to next step if steering column remains locked and scan tool displays the

following BCM data:

z Steering Column Lock State - IGN OFF LOCKED z Key In Ignition - ACTIVE z Key Out Of Ignition - ACTIVE (will not change) z Column Feedback - INACTIVE

If conditions are not met, go to STEERING COLUMN LOCK MALFUNCTION .

5. Turn ignition on. System is okay if steering column unlocks and scan tool displays the following BCM data:

z Steering Column Lock State - IGN ON UNLOCKED z Key In Ignition - ACTIVE z Key Out Of Ignition - ACTIVE (will not change) z Column Feedback - ACTIVE

If conditions are not met, go to STEERING COLUMN LOCK MALFUNCTION .

STEERING COLUMN LOCK MALFUNCTION

NOTE: Use this test procedure when STEERING COLUMN LOCK message is displayed

or steering column does not lock or unlock.

1. Perform BCM DIAGNOSTIC SYSTEM CHECK in BODY CONTROL MODULE article.

2. Using scan tool, retrieve BCM DTCs. If steering column DTC B2587, B2588, B2592 or B2593 are stored, perform BCM DIAGNOSTIC SYSTEM CHECK in BODY CONTROL MODULE article.

3. If steering column connector C207 was disconnected with ignition on, go to step 16). See WIRING DIAGRAMS . If connector C207 was not disconnected, go to next step.

4. Turn ignition on. Using scan tool, check BCM steering column lock state. If display is ENABLE STDBY, go to step 7). If display is not ENABLE STDBY, go to next step.

5. Turn ignition off. Using scan tool, check BCM Key In Ignition status with key in ignition. Display should read ACTIVE. Check BCM Key In Ignition status with key out of ignition. Display should read INACTIVE. If display is correct, go to next step. If display is not as specified, diagnose and repair Key In Ignition circuits between ignition switch and BCM. See WIRING DIAGRAMS

6. Disconnect steering column connector C207. Using scan tool, check BCM Key Out Of Ignition status with key in ignition. Display should read ACTIVE. Check BCM Key Out Of Ignition status with key out of ignition. Display should read INACTIVE. If display is correct, go to step 8). If display is not as specified, go to step 11).

7. Using test light connected to battery voltage, probe harness connector C207 terminal "A". If test light illuminates, go to next step. If test light does not illuminate, go to step 10).

8. Remove key from ignition switch. Connect test light between harness connector C207 terminal "C" and terminal "D". Usin

scan tool, cycle steering column lock/unlock motor. If test light illuminates in both

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lock and unlock positions, go to step 13). If light did not illuminate in both positions, go to step 12).

9. Check for open or short to ground in Light Green wire between steering wheel lock connector C207 terminal "B" and BCM connector C2 terminal C15. If an open or short was found, repair as necessary and go to step 16). If no problem was found, go to step 13).

10. Repair open circuit in Black wire between steering wheel lock connector C207 terminal "A" and ground. Go to step 16).

11. Check for open in Tan wire between BCM connector C3 terminal B8 and ignition switch connector C2 terminal "D". If an open was found, repair as necessary and go to step 16). If no problem was found, go to step 14).

12. Check for an open or short to ground in Orange wire between steering wheel lock connector C207 terminal "D" and BCM connector C3 terminal A8. Check for an open or short to ground in Purple wire between steering wheel lock connector C207 terminal "C" and BCM connector C3 terminal A6. If an open or short was found, repair as necessary and go to step 16). If no problem was found, go to step 15).

13. Replace steering column lock motor. Go to step 16).

14. Replace ignition lock cylinder. Go to step 16).

15. Replace BCM. Program BCM. See PROGRAMMING . Go to step 16).

16. Turn ignition off. Disconnect BCM fuse No. 25 for 15 seconds to clear BCM steering column fail enable mode. Reinstall and reconnect components and connectors. Turn ignition on. Clear DTCs. Perform BCM DIAGNOSTIC SYSTEM CHECK in BODY CONTROL MODULE article.

DIAGNOSTIC TESTS

DTC that affects UTD operation can be stored in different systems. Refer to DIAGNOSTIC TROUBLE CODE (DTC) DEFINITIONS table for UTD related DTCs. To access or clear DTCs, use scan tool or Instrument Panel Cluster clearing DTC feature.

DIAGNOSTIC TROUBLE CODE (DTC) DEFINITIONS

DTC Definition

B2236 B2237 B2252 B2253 B2587 B2588 B2592 B2593 B2721 B2722 B2723 B2735

(1) (2) (1) (2) (3) (3) (3) (3) (3) (3) (3) (3)

PASS-Key(R) Detection Circuit (Out Of Range)

PASS-Key(R) Detection Circuit (Short To Ground)

PASS-Key(R) Detection Circuit (Open/Short To Voltage)

PASS-Key(R) Programming Mode Active

Left Door Lock Switch Fault

Right Door Lock Switch Fault

Key Cylinder Switch Fault

Key Cylinder Switch Fault Column Lock/Unlock Drive "A" Column Lock/Unlock Drive "A" Column Lock/Unlock Drive "B" Column Lock/Unlock Drive "B"

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U1016 P1626 P1630 P1630

(1) (2)

(3) (4) (4) (4)

Theft Deterrent System Fuel Enable Circuit

Theft Deterrent Password Incorrect

Left Door Control Module (LDCM) code. See procedures in KEYLESS ENTRY SYSTEM article. Right Door Control Module (RDCM) code. See procedures in KEYLESS ENTRY SYSTEM

PCM Communication Loss

Theft Deterrent In Learn Mode

article.

(3)

See BODY CONTROL MODULE article for diagnosis and repair.

(4)

See TESTS W/CODES article in ENGINE PERFORMANCE.

TESTING - ARMING & DISARMING UTD SYSTEM

ARMING

When any door or hatch is open, SECURITY indicator light will flash as a reminder to arm system. Light will turn off if there is no change after 10 minutes. To arm system, turn ignition off. With a door open, lock doors with power lock switch or Remote Keyless Entry (RKE) transmitter. For more information on remote transmitter and RFA system, see KEYLESS ENTRY SYSTEM article. If passive switch is on, walking out of range with remote transmitter will also activate system. Indicator light will stay on. Light will turn off if there is no change after 10 minutes. Locking doors manually will not arm system. When doors and hatch are closed, system is in doors and hatch armed mode. If both doors are closed, but hatch is open, system is in DOORS ARMED mode. System will monitor doors only for intrusion. If hatch is closed, alarm will not be activated. If unauthorized entry is detected, system goes into ALARM mode. Alarm mode sounds horns and/or flashes lights, depending on personalize options. Alarm continues for 2 minutes (30 seconds on export models). Ignition and fuel system are also disabled. This is followed by 3 minute period when horn is not sounded. System then returns to ARMED mode, unless a disarm input is received.

DISARMING SYSTEM

To disarm system, insert oval head key in door lock cylinder and unlock, or insert correct key in ignition switch and turn ignition on, or press UNLOCK button on remote transmitter. If RFA system passive switch is on, system will disarm when remote transmitter is within range. For more information on remote transmitter and RFA system, see KEYLESS ENTRY SYSTEM

article. Disconnecting battery, removing fuses or using inside

manual or power door lock switch to unlock door will not disable alarm mode.

REMOVAL & INSTALLATION

WARNING: Deactivate air bag system before performing any service operation. See

AIR BAG RESTRAINT SYSTEM article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.

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CAUTION: When battery is disconnected, vehicle computer and memory systems

may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION section before disconnecting battery.

STEERING WHEEL COLUMN LOCK

Removal

Remove tilt wheel lever by releasing locking tab and pulling out lever. Remove air bag. Remove steering wheel. Remove knee bolster trim panel. Remove upper and lower column covers. Disconnect wiring harness connectors. Remove snap ring and SIR coil. Compress shaft lock shield using SIR Tool (J 23653). Remove retaining ring, wave washer and shield. Remove screws and electronic column lock from column. See Fig. 1

Installation

To install, reverse removal procedure. Use NEW retaining ring and steering wheel nut. Torque steering wheel nut to 30 ft. lbs. (41 N.m).

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Fig. 1: Removing Electronic Column Lock Courtesy of GENERAL MOTORS CORP.

WIRING DIAGRAMS

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Fig. 2: Anti-Theft System Wiring Diagram

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BODY CONTROL MODULE

1998 ACCESSORIES & EQUIPMENT General Motors Corp. - Body Control Module

DESCRIPTION

WARNING: Deactivate air bag system before performing any service operation. See

AIR BAG RESTRAINT SYSTEM article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.

The Body Control Module (BCM) communicates with various systems over the serial data line in order to control the following functions: Bulb over-voltage protection; door, hatch and hood ajar status; exterior and interior lighting control; hatch release control; heated mirror control; horn relay; key-in-ignition status; load shed control; monitored loads control; PASS-Key(R) system; power mode master; rear defogger control; steering column lock/unlock control; Traction Control System (TCS) activation control; Universal Theft Deterrent (UTD); and vehicle configuration (RPO codes).

Some vehicle systems share data over a serial data line to execute various vehicle functions. Communication between each system is accomplished by sending digitally coded messages, which consist of specific information the system module must follow. Each system module is assigned its own recognition code, so that it can respond to appropriate messages. The BCM acts as the power mode master, which can determine state of health of other systems.

Signals that activate the BCM are known as "wake-up" signals. BCM is asleep when it is not controlling or monitoring the following wake-up functions: Any activity on serial data line, hatch or door ajar switch, hatch release switch, key-in-ignition switch, monitored load relay, any exterior lighting function, battery disconnection and reconnection, or ignition is turned on. The BCM will enter a sleep state when all of the following conditions exist: No activity on serial data line, ignition is turned off, no outputs are commanded, no delay timers are actively counting and no wake-up inputs are present.

OPERATION

The BCM has 2 main power feeds (high and low current) and 2 main grounds. Low power feed (battery 1) is used to supply power for BCM's logic and internal driver operation. Operating current at low power feed should not exceed 3 amps. High power feed is used to supply power for systems that draw higher amounts of current. Operating current at high power feed should not exceed 7.5 amps for 2 seconds when BCM is awake, or 2.5 milliamps when BCM is asleep. For most functions, BCM system voltage should be 9-16 volts. If voltage exceeds 16 volts, BCM will disable functions that could be damaged.

The BCM can detect if certain electrical loads have been left on to minimize the possibility of battery rundown. When BCM detects that ignition has been turned off, BCM immediately checks status of load monitor input. If BCM detects that a load is present (ground on circuit No. 640), BCM will turn on load monitor relay for 15 minutes. If BCM detects load is still present after 15 minutes, BCM will turn off relay, removing battery voltage from loads. If a switch transition is then detected by BCM, BCM will turn on relay again for another 15-minute

eriod.

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BCM can turn off rear window defogger and heated outside mirror electrical loads when vehicle is experiencing conditions that will allow these loads to discharge the battery. BCM will also turn off these loads if engine demands are higher. BCM will disable interior light bulbs if system voltage exceeds 18 volts, in order to extend bulb life.

By using the ignition switch and door ajar inputs, BCM can detect if driver has left the vehicle. If ignition is turned off and no door ajar status is detected, BCM assumes that driver is in vehicle. As soon as BCM receives a door ajar signal, it will assume that driver has left vehicle. This information is used for Retained Accessory Power (RAP) functions.

If a BCM malfunction would result in unacceptable vehicle operation, BCM will take fail-soft action to minimize the condition (i.e., BCM will substitute a fixed input or output value if BCM is unable to interpret data).

COMPONENT LOCATIONS

Component Location

Body Control Module (BCM) Data Link Connector (DLC) Behind Left Side Of Instrument Panel, Below Steering

Brake Transmission Shift Interlock (BTSI) Solenoid

Daytime Running Light (DRL) Control Module

Door Ajar Indicator Switch Rear Of Door, Integral With Latch Door Control Module (DCM) Behind Bottom Center Of Door Trim Panel Electronic Traction/Suspension Control

System (TCS) Switch Foglight/Rear Compartment Lid Release

Switch Hood Ajar Switch Engine Compartment Support Bracket HVAC Control Head Center Of Instrument Panel, Under Radio Ignition Switch Left Side Of Instrument Panel, Between Radio &

Instrument Panel Electrical Center Behind Carpet In Right Footwell, Mounted To Toe

Powertrain Control Module (PCM) Right Rear Corner Of Engine Compartment, Under

Right Rear Compartment Lid Lock Release Solenoid

Star Connectors No. 1 & 2 In DLC Instrument Panel Harness Steering Wheel Lock Right Side Of Steering Column, Behind Instrument Panel

(1)

In Center Console, Between Gearshift Lever Storage Box

Behind Carpet In Right Footwell, Mounted To Toe

Board

Column

In Center Console, Integral With Gearshift Lever

Behind Instrument Cluster

In Instrument Panel, To Left Of Steering Column

Steering Column

Board

Battery

Right Side Of Rear Compartment, On Right

Compartment Latch

Page 18

Underhood Electrical Center Right Rear Corner Of Engine Compartment, Between

Battery & Coolant Reservoir

(1)

See Fig. 6 .

BCM PROGRAMMING/RPO CONFIGURATION

NOTE: Following procedure is written specifically for General Motors' Tech 2 scan tool.

A generic scan tool may not be capable of performing all necessary programming functions.

Description

BCM's Electronically Erasable Programmable Only Memory (EEPROM) chip must be programmed with

roper RPO configurations. EEPROM stores information about vehicle options and point of sale. When BCM is

replaced, new BCM must be programmed to identify the following information:

z Real Time Damping (RTD). z Memory options. z Daytime Running Lights (DRL). z Front foglights. z Tire Pressure Monitor (TPM). z HVAC (manual or automatic). z Country of sale (US, Canada, Europe, etc.).

If BCM is not properly configured, BCM will set default values for some systems, which may cause faults in other systems.

Since BCM sends a password to PCM, PCM must also be programmed to accept the new password. BCM

rogramming procedure will enable learn password mode for BCM and PCM (this mode allows PCM to learn new password sent by BCM whenever BCM or PCM is replaced). If BCM is not properly programmed, vehicle will exhibit a no-crank condition.

When BCM is replaced, new BCM must be programmed to accept resistance value of existing vehicle keys so that it will allow PASS-Key(R) operation. The new BCM is programmed to accept the first PASS-Key(R) resistance value detected. If BCM is unable to detect a valid PASS-Key(R) resistance value, BCM will not end

rogramming sequence and DTC 2735 will set.

NOTE: Maintain proper battery voltage during programming procedure and perform

steps as specified, or programming procedure will have to be repeated.

NOTE: When programming procedure is performed, DTC P1630 will set (this is normal).

When DTC P1630 sets, turn ignition off for 30 seconds, then turn ignition on. DTC P1630 should clear. If DTC P1630 does not clear, see TESTS W/CODES

Page 19

article in ENGINE PERFORMANCE section.

Programming Procedure

1. Using scan tool, select NEW BCM SETUP. Program BCM with correct RPO code configuration. Go to next step.

2. Using scan tool, check for proper communication between BCM and PCM. If components cannot communicate, diagnose and repair problem as necessary. If BCM and PCM are communicating properly, go to next step.

3. Turn ignition on (engine off) for 11 minutes. Turn ignition off for 30 seconds. Turn ignition on (engine off) for 11 minutes. Turn ignition off for 30 seconds. Turn ignition on (engine off) for 11 minutes or until DTC P1630 sets. Turn ignition off for 30 seconds. Turn ignition on (engine off) for 30 seconds. Attempt to start engine. If engine starts and runs normally, go to next step. If engine does not start and run normally, go to step 5).

4. Using scan tool, check for DTCs. Clear PCM DTCs. Turn ignition off for 30 seconds. Attempt to start engine. If engine starts and runs normally, programming procedure is complete. If engine does not start and run normally, go to next step.

5. If DTC P1626, P1630 or P1631 is set, see TESTS W/CODES article in ENGINE PERFORMANCE section. If DTC P1626, P1630 or P1631 is not set, go to step 2).

SELF-DIAGNOSTIC SYSTEM

Body Control Module (BCM) is equipped with a self-diagnostic system, which detects system Diagnostic Trouble Codes (DTCs) or abnormalities. When a malfunction occurs, BCM will store a DTC. See BCM DTC DEFINITIONS table. Malfunctions are recorded as history/intermittent failures or as current failures. Current DTCs indicate BCM has detected a fault which is currently present. A history DTC indicates that BCM has

reviously detected a malfunction that is not currently present.

Instrument Panel Cluster (IPC) can be used to retrieve and clear DTCs. See INSTRUMENT PANEL article. A scan tool can be used to retrieve and clear DTCs. The scan tool also has several features that can be used to help locate an intermittent condition. When scan tool is used for system tests, it will display values actually seen or commanded by various systems (i.e., BCM, PCM). This will usually include the following types of information:

z Analog Data Input - Displays analog input seen by system. z Inputs/Outputs - Displays digital values as seen by system, and provides indication of whether input or

output has cycled.

z Special Functions (Output Controls) - Allows for outputs of system to be set at a desired value (ON or

OFF). This will only indicate if BCM is sending the appropriate commands, not what action was actually taken.

z Clear Codes - Will erase DTCs for system currently selected (if problem still exists in system, DTC may

immediately reset).

CLEARING DTCS

If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. To

Page 20

manually clear DTCs, use scan tool or press RESET button on IPC's Driver Information Center (DIC).

BCM DTC DEFINITIONS

Code No. Circuit Affected

B0432 Rear Defogger Relay Circuit Open Or Short To Ground) B0433 Rear Defogger Relay Circuit Short To Voltage Or BCM Open) B0502 RH DRL Relay Circuit Open Or Short To Ground) B0503 RH DRL Relay Circuit Short To Voltage Or BCM Open) B0507 LH DRL Relay Circuit Open Or Short To Ground) B0508 LH DRL Relay Circuit Short To Voltage Or BCM Open) B0605 BCM Internal Memory Malfunction

B0844

(1)

BCM Temporarily Inhibit ABS

B2403 Front Foglight Switch Circuit Short To Voltage) B2408

(2)

Rear Foglight Switch Circuit Short To Voltage) B2482 Back-Up Light Relay Circuit Open Or Short To Ground) B2483 Back-Up Light Relay Circuit Short To Voltage Or BCM Open) B2527 Horn Relay Circuit Open Or Short To Ground) B2528 Horn Relay Circuit Short To Voltage Or BCM Open) B2573 Hatch Release Switch Circuit Short To Voltage) B2578 RF Turn Signal Monitor Circuit Short To Voltage) B2583 LF Turn Signal Monitor Circuit Short To Voltage) B2587 Column Lock/Unlock Drive "A" Open Or Short To Ground) B2588 Column Lock/Unlock Drive "A" Open Or Short To Voltage) B2592 Column Lock/Unlock Drive "B" Open Or Short To Ground) B2593 Column Lock/Unlock Drive "B" Open Or Short To Voltage) B2597 TCS Switch Circuit Short To Ground) B2721 PASS-Key(R) Detection Circuit Out Of Range) B2722 PASS-Key(R) Detection Circuit Short To Ground) B2723 PASS-Key(R) Detection Circuit Short To Voltage Or Open) B2735 PASS-Key(R) Programming Mode Active U1016

U1096

(3)

Loss Of Communication With PCM

(3)

Loss Of Communication With IPC

U1255 Serial Data Line Malfunction

(1)

Information not available at time of publication.

(2)

Export only.

(3)

No State Of Health (SOH) message received.

Page 21

DIAGNOSTIC TESTS

NOTE: For wiring and connector terminal identification, see WIRING DIAGRAMS .

NOTE: When testing procedure indicates to probe or check a terminal, use adapters

from Connector Test Adapter Kit (J-35616-A). This will ensure terminal will not be damaged, and that connection is okay.

SCAN TOOL DOES NOT COMMUNICATE WITH SERIAL DATA LINE

NOTE: To identify wire colors and modules on serial data line, see DATA LINK

CONNECTORS and POWER DISTRIBUTION under WIRING DIAGRAMS

Testing

1. Turn ignition off. Connect scan tool. Disconnect bus bars from Black 12-pin star connectors No. 1 and 2.

See COMPONENT LOCATIONS . Connect Serial Data Link Tester (J-42236) to both star connectors. Ensure star connectors correctly correspond with serial data link testing connectors No. 1 and 2. Using serial data link tester, put switch in STAR CONNECTOR #1 position. Rotate rotary switch to "M" position. Turn ignition on. Using scan tool, attempt to establish communication with BCM. If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, go to step 4).

2. Ensure switch on serial data link tester is in STAR CONNECTOR #1 position. Using scan tool, attempt to establish communication with the following vehicle systems by rotating rotary switch on serial data link tester as specified:

z "L" - Heating, Ventilation and A/C (HVAC) system. z "J" - Remote Function Actuator (RFA) system. z "H" - Real Time Damping (RTD) system (if equipped). z "G" - Instrument Panel Cluster (IPC). z "E" - Traction Control System (TCS). z "D" - Radio system. z "B" - Powertrain Control Module (PCM).

If scan tool communicates with each system, go to next step. If scan tool does not communicate with each system, go to step 7).

3. Turn switch on serial data link tester to STAR CONNECTOR #2 position. Using scan tool, attempt to establish communication with the following vehicle systems by rotating rotary switch on serial data link tester as specified:

z "C" - Left Door Control Module (DCM) system. z "D" - Right Door Control Module (DCM) system z "K" - Seat Control Module (SCM) system (if equipped).

If scan tool communicates with each s

stem, go to step 9). If scan tool does not communicate with each

Page 22

system, go to step 7).

4. Turn ignition off. Disconnect serial data link tester. Ensure bus bars are still disconnected from star connectors No. 1 and 2. Using DVOM, check continuity of Purple wire between DLC connector terminal No. 2 and star connector No. 1 terminal "A". If continuity exists, go to next step. If continuity does not exist, go to step 10).

5. Check continuity between DLC connector terminal No. 2 (Purple wire) and ground. If continuity exists, go to step 10). If continuity does not exist, go to next step.

6. Turn ignition on. Using DVOM, check voltage between DLC connector terminal No. 2 (Purple wire) and ground. If any voltage exists, go to step 10). If no voltage exists, go to next step.

7. Turn ignition off. Disconnect appropriate system module for system that did not communicate with scan tool. Using DVOM, check for continuity between appropriate terminal on appropriate star connector and ground. If continuity exists, go to step 11). If continuity does not exist, go to next step.

8. Turn ignition on. Using test light connected to ground, probe appropriate terminal on appropriate star connector for system that is not communicating. If test light illuminates, go to step 12). If test light does not illuminate, go to step 13).

9. Check for intermittent short to ground, short to voltage or open in serial data line circuits. If no problem is found, system is operating properly. If problem is found, repair as necessary. Go to step 14).

10. Repair short to ground, short to voltage or open in Purple wire between DLC and star connector No. 1. Go to step 14).

11. Repair short to ground in appropriate wire between unresponsive module and appropriate star connector. Go to step 14).

12. Repair short to voltage in appropriate wire between unresponsive module and appropriate star connector. Go to step 14).

13. Replace appropriate module. Go to next step.

14. Turn ignition off. Reinstall all components or connectors. Clear DTCs. Ensure system is operating properly.

BCM DIAGNOSTIC SYSTEM CHECK

NOTE: Use this check as the starting point for any BCM complaint. BCM is a very

reliable component, and is not likely the cause of malfunction. Most malfunctions are caused by faulty wiring, connectors or components.

Testing

1. Turn ignition off. Connect scan tool. Turn ignition on. Attempt to establish communication with BCM. If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, go to step 3).

2. Using scan tool, check for BCM DTCs. If any DTC exists, go to appropriate DTC test. If no DTCs exist, system is operating properly.

3. Attempt to establish communication with other systems connected to same serial data line (PCM, RFA, IPC, etc.). If scan tool communicates with other systems, go to next step. If scan tool does not communicate with other systems, go to SCAN TOOL DOES NOT COMMUNICATE WITH SERIAL

Page 23

DATA LINE .

4. Ensure ignition is on. Using a test light connected to ground, probe each BCM fuse. See WIRING DIAGRAMS . If test light illuminates at all circuits, go to next step. If test light does not illuminate at all circuits, go to step 9).

5. Turn ignition off. Disconnect BCM 24-pin connector C1, 32-pin connector C2 and 16-pin connector C3. Turn ignition on. Using a test light connected to ground, probe each BCM power circuit. See WIRING DIAGRAMS . If test light illuminates at all circuits, go to next step. If test light does not illuminate at all circuits, go to step 11).

6. Using a test light connected to battery, probe each BCM ground circuit. See WIRING DIAGRAMS . If test light illuminates at all circuits, go to next step. If test light does not illuminate at all circuits, go to step 12).

7. Using DVOM, check for continuity between BCM harness connector C1, terminal B6 (Light Green wire) and Data Link Connector (DLC) terminal No. 2 (Purple wire). If continuity exists, go to next step. If continuity does not exist, go to step 10).

8. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to step 13).

9. Repair open in ignition or battery feed to BCM fuse. If any fuse is open, locate and repair short in associated circuit. See WIRING DIAGRAMS . Go to step 13).

10. Locate and repair open in Light Green or Purple wire between BCM connector C1 and DLC. Go to step

13).

11. Locate and repair open in BCM power circuit. Go to step 13).

12. Locate and repair open in BCM ground circuit. Go to next step.

13. Turn ignition off. Reinstall all components or connectors. Clear DTCs. Ensure system is operating properly.

Diagnostic Aids

1. The following conditions may result in intermittent operation of BCM with no DTC stored:

z Any condition which results in interruption of power to BCM. z Out of range battery or ignition voltage (normal BCM operating voltage is 9-16 volts). z Loose or damaged ground(s). z Open or shorted serial data line.

2. BCM tests for different malfunctions during different vehicle conditions. A thorough test drive may be necessary to repeat malfunction. Most intermittent problems are caused by faulty electrical connections or wiring. Check for: poor connections, backed-out terminals, dirty or corroded terminals, chafed wires, or damaged connectors.

DTC B0432: REAR DEFOGGER RELAY CIRCUIT (OPEN OR SHORT TO GROUND)

Description

When BCM receives a defogger ON request from rear defogger switch when engine is running, BCM will

round circuit No. 193 (White wire) to energize rear defogger relay. BCM monitors voltage level on rear

Page 24

defogger control circuit. When BCM activates rear defogger relay, voltage level in control circuit should be low. When relay is not activated, voltage level in control circuit should be high.

DTC B0432 will set when BCM detects a low voltage level in circuit No. 193 (White wire) for 2 seconds when it is not energizing rear defogger relay. No driver warning message will be displayed.

DTC B0432 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B0432 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B0432 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Turn ignition off. Disconnect rear defogger relay from instrument panel electrical center. Turn ignition on. Using a test light connected to ground, probe rear defogger relay BATT terminals at instrument panel electrical center. See Fig. 1 . If test light illuminates, go to next step. If test light does not illuminate, go to step 14).

3. Turn ignition off. Using a test light connected to battery, probe rear defogger relay CKT 193 terminal at instrument panel electrical center. See Fig. 1 . If test light illuminates, go to step 11). If test light does not illuminate, go to next step.

4. Using DVOM, check resistance between rear defogger relay terminals No. 85 and 86. If resistance is 75105 ohms, go to next step. If resistance is not 75-105 ohms, go to step 13).

5. Check for continuity between rear defogger relay terminals No. 85 and 87. If continuity exists, go to step

13). If continuity does not exist, go to next step.

6. Check for continuity between rear defogger relay terminals No. 85 and 30. If continuity exists, go to step

13). If continuity does not exist, go to next step.

7. Turn ignition on. Using a test light connected to battery, probe rear defogger relay CKT 193 terminal at instrument panel electrical center. See Fig. 1

. Using scan tool, command rear defogger relay on and off. If test light toggles on and off as commanded, go to step 9). If test light does not toggle on and off as commanded, go to next step.

8. Check for an open in instrument panel electrical center or in circuit No. 193 (White wire) between BCM connector C2 and rear defogger relay. If no problem is found, go to step 10). If problem is found, repair as necessary. Go to step 16).

9. Check for intermittent malfunction in rear defogger circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 16).

10. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Using scan tool, cycle rear defogger relay. If DTC B0432 is current, go to step 15). If DTC B0432 is not current, system is operating properly.

11. Ensure ignition is off. Disconnect BCM 32-pin connector C2. Using a test light connected to battery, probe rear defogger relay CKT 193 terminal at instrument panel electrical center. See Fig. 1 . If test light

Page 25

illuminates, go to next step. If test light does not illuminate, go to step 15).

12. Repair short to ground in instrument panel electrical center or in circuit No. 193 (White wire) between BCM connector C2 and rear defogger relay. Go to step 16).

13. Replace rear defogger relay. Go to step 16).

14. Repair open in ignition feed circuit to instrument panel electrical center. See POWER DISTRIBUTION under WIRING DIAGRAMS . If a fuse is open, repair short in appropriate circuit. Go to step 16).

15. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

16. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. Rear defogger relay may be installed in instrument panel electrical center in 2 directions, and still function properly. The following conditions may cause an intermittent: Intermittent short to ground or open in circuit No. 193 (White wire) between BCM and rear defogger relay; poor connections at BCM, instrument panel electrical center or rear defogger relay; or internal open or short in rear defogger relay.

2. If circuit No. 193 (White wire) between BCM and rear defogger relay is shorted to ground, rear defogger will stay on at all times. If circuit No. 193 (White wire) between BCM and rear defogger relay is open, rear defogger will stay off at all times.

Page 26

Fig. 1: Identifying Rear Defogger Relay Terminals At Instrument Panel Electrical Center Courtesy of GENERAL MOTORS CORP.

DTC B0433: REAR DEFOGGER RELAY CIRCUIT (SHORT TO VOLTAGE OR BCM OPEN)

Description

When BCM receives a defogger ON request from rear defogger switch when engine is running, BCM will ground circuit No. 193 (White wire) to energize rear defogger relay. BCM monitors voltage level on rear defogger control circuit. When BCM activates rear defogger relay, voltage level in control circuit should be low. When relay is not activated, voltage level in control circuit should be high.

DTC B0433 will set when BCM detects a high voltage level in circuit No. 193 (White wire) for 2 seconds when it is energizing rear defogger relay. No driver warning message will be displayed.

Page 27

DTC B0433 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B0433 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B0433 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Turn ignition off. Disconnect rear defogger relay from instrument panel electrical center. Turn ignition on. Using a test light connected to ground, probe rear defogger relay CKT 193 terminal at instrument panel electrical center. See Fig. 1 . If test light illuminates, go to step 10). If test light does not illuminate, go to next step.

3. Using DVOM, check resistance between rear defogger relay terminals No. 85 and 86. If resistance is 75105 ohms, go to next step. If resistance is not 75-105 ohms, go to step 12).

4. Check for continuity between rear defogger relay terminals No. 85 and 87. If continuity exists, go to step

12). If continuity does not exist, go to next step.

5. Check for continuity between rear defogger relay terminals No. 85 and 30. If continuity exists, go to step

12). If continuity does not exist, go to next step.

6. Turn ignition on. Using a test light connected to battery, probe rear defogger relay CKT 193 terminal at instrument panel electrical center. See Fig. 1 . Using scan tool, command rear defogger relay on and off. If test light toggles on and off as commanded, go to step 8). If test light does not toggle on and off as commanded, go to next step.

7. Check for an open in instrument panel electrical center or in circuit No. 193 (White wire) between BCM connector C2 and rear defogger relay. If no problem is found, go to step 9). If problem is found, repair as necessary. Go to step 14).

8. Check for intermittent malfunction in rear defogger circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 14).

9. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Using scan tool, cycle rear defogger relay. If DTC B0433 is current, go to step 13). If DTC B0433 is not current, system is operating properly.

10. Turn ignition off. Disconnect BCM 32-pin connector C2. Turn ignition on. Using a test light connected to

ground, probe rear defogger relay CKT 193 terminal at instrument panel electrical center. See Fig. 1

. If

test light illuminates, go to next step. If test light does not illuminate, go to step 13).

11. Repair short to voltage in instrument panel electrical center or in circuit No. 193 (White wire) between BCM connector C2 and rear defogger relay. Go to step 14).

12. Replace rear defogger relay. Go to step 14).

13. Replace BCM. See REMOVAL & INSTALLATION

. Reprogram BCM. See BCM

PROGRAMMING/RPO CONFIGURATION . Go to next step.

14. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Page 28

Diagnostic Aids

1. Rear defogger relay may be installed in instrument panel electrical center in 2 directions, and still function properly. The following conditions may cause an intermittent: Intermittent short to voltage in circuit No. 193 (White wire) between BCM and rear defogger relay; poor connections at BCM, instrument panel electrical center or rear defogger relay; or internal short to voltage in rear defogger relay.

2. If circuit No. 193 (White wire) between BCM and rear defogger relay is shorted to voltage or if BCM is open internally, rear defogger will stay off at all times.

DTC B0502: RH DRL RELAY CIRCUIT (OPEN OR SHORT TO GROUND)

Description

BCM grounds circuit No. 1966 (Light Green wire) to energize RH DRL relay and turn right front turn signal on. This allows right front turn signal to be used in Daytime Running Lights (DRL), Underhood Theft Deterrent (UTD) and approach lighting functions.

BCM monitors voltage level on circuit No. 1966 (Light Green wire). When BCM activates RH DRL relay, voltage level in control circuit should be low. When relay is not activated, voltage level in control circuit should be high.

DTC B0502 will set when BCM detects a low voltage level in circuit No. 1966 (Light Green wire) for 2 seconds when it is not energizing RH DRL relay. No driver warning message will be displayed.

DTC B0502 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B0502 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B0502 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK

2. Turn ignition off. Disconnect RH DRL relay from instrument panel electrical center. Turn ignition on. Using a test light connected to ground, probe RH DRL relay BATT terminals at instrument panel electrical center. See Fig. 2

. If test light illuminates, go to next step. If test light does not illuminate, go to

step 13).

3. Turn ignition off. Using a test light connected to battery, probe RH DRL relay CKT 1966 terminal at instrument panel electrical center. See Fig. 2

. If test light illuminates, go to step 10). If test light does not

illuminate, go to next step.

4. Using DVOM, check resistance between RH DRL relay terminals No. 85 and 86. If resistance is 75-105 ohms, go to next step. If resistance is not 75-105 ohms, go to step 12).

5. Check for continuity between RH DRL relay terminals No. 85 and 30. If continuity exists, go to step 12).

Page 29

If continuity does not exist, go to next step.

6. Turn ignition on. Using a test light connected to battery, probe RH DRL relay CKT 1966 terminal at instrument panel electrical center. See Fig. 2

. Using scan tool, command RH DRL relay on and off. If test light toggles on and off as commanded, go to step 8). If test light does not toggle on and off as commanded, go to next step.

7. Turn ignition off. Disconnect BCM 32-pin connector C2. Using DVOM, check for continuity between BCM harness connector C2, terminal D16 (Light Green wire) and RH DRL relay CKT 1966 terminal at instrument panel electrical center. See Fig. 2

. If continuity exists, go to step 15). If continuity does not

exist, go to step 14).

8. Check for intermittent malfunction in RH DRL circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 16).

9. Ensure ignition is off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Using scan tool, cycle RH DRL relay. If DTC B0502 is current, go to step 15). If DTC B0502 is not current, system is operating properly.

10. Ensure ignition is off. Disconnect BCM 32-pin connector C2. Using a test light connected to battery,

probe RH DRL relay CKT 1966 terminal at instrument panel electrical center. See Fig. 2 . If test light illuminates, go to next step. If test light does not illuminate, go to step 15).

11. Repair short to ground in instrument panel electrical center or in circuit No. 1966 (Light Green wire) between BCM connector C2 and RH DRL relay. Go to step 16).

12. Replace RH DRL relay. Go to step 16).

13. Repair open in ignition feed circuit to instrument panel electrical center. See POWER DISTRIBUTION under WIRING DIAGRAMS . If a fuse is open, repair short in appropriate circuit. Go to step 16).

14. Repair open in instrument panel electrical center or in circuit No. 1966 (Light Green wire) between BCM connector C2 and RH DRL relay. Go to step 16).

15. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

16. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to ground or open in circuit No. 1966 (Light Green wire) between BCM and RH DRL relay; poor connections at BCM, instrument panel electrical center or RH DRL relay; or internal open or short in RH DRL relay.

2. If circuit No. 1966 (Light Green wire) between BCM and RH DRL relay is shorted to ground, RH DRL will stay on at all times. If circuit No. 1966 (Light Green wire) between BCM and RH DRL relay is open, RH DRL will sta

off at all times.

Page 30

Fig. 2: Identifying RH DRL Relay Terminals At Instrument Panel Electrical Center

Courtesy of GENERAL MOTORS CORP.

DTC B0503: RH DRL RELAY CIRCUIT (SHORT TO VOLTAGE OR BCM OPEN)

Description

e high.

Page 31

DTC B0503 will set when BCM detects a high voltage level in circuit No. 1966 (Light Green wire) for 2 seconds when it is energizing RH DRL relay. No driver warning message will be displayed.

DTC B0503 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B0503 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B0503 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Turn ignition off. Disconnect RH DRL relay from instrument panel electrical center. Turn ignition on. Using a test light connected to ground, probe RH DRL relay CKT 1966 terminal at instrument panel electrical center. See Fig. 2 . If test light illuminates, go to step 8). If test light does not illuminate, go to next step.

3. Using DVOM, check resistance between RH DRL relay terminals No. 85 and 86. If resistance is 75-105 ohms, go to next step. If resistance is not 75-105 ohms, go to step 11).

4. Turn ignition on. Using a test light connected to battery, probe RH DRL relay CKT 1966 terminal at instrument panel electrical center. See Fig. 2 . Using scan tool, command RH DRL relay on and off. If test light toggles on and off as commanded, go to step 6). If test light does not toggle on and off as commanded, go to next step.

5. Turn ignition off. Disconnect BCM 32-pin connector C2. Using DVOM, check for continuity between BCM harness connector C2, terminal D16 (Light Green wire) and RH DRL relay CKT 1966 terminal at instrument panel electrical center. See Fig. 2 . If continuity exists, go to step 12). If continuity does not exist, go to step 9).

6. Check for intermittent malfunction in RH DRL circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 13).

7. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Using scan tool, cycle RH DRL relay. If DTC B0503 is current, go to step 12). If DTC B0503 is not current, system is operating properly.

8. Turn ignition off. Disconnect BCM 32-pin connector C2. Turn ignition on. Using a test light connected to ground, probe RH DRL relay CKT 1966 terminal at instrument panel electrical center. See Fig. 2 . If test light illuminates, go to step 10). If test light does not illuminate, go to step 12).

9. Repair open in instrument panel electrical center or in circuit No. 1966 (Light Green wire) between BCM connector C2 and RH DRL relay. Go to step 13).

10. Repair short to voltage in instrument panel electrical center or in circuit No. 1966 (Light Green wire) between BCM connector C2 and RH DRL relay. Go to step 13).

11. Replace RH DRL relay. Go to step 13).

12. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION. Go to next step.

13. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

Page 32

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to voltage in circuit No. 1966 (Light Green wire) between BCM and RH DRL relay; poor connections at BCM, instrument panel electrical center or RH DRL relay; or internal short to voltage in RH DRL relay.

2. If circuit No. 1966 (Light Green wire) between BCM and RH DRL relay is shorted to voltage or if BCM is open internally, RH DRL will stay off at all times.

DTC B0507: LH DRL RELAY CIRCUIT (OPEN OR SHORT TO GROUND)

Description

BCM grounds circuit No. 1976 (Orange/Black wire) to energize LH DRL relay and turn left front turn signal on. This allows left front turn signal to be used in Daytime Running Lights (DRL), Underhood Theft Deterrent (UTD) and approach lighting functions.

BCM monitors voltage level on circuit No. 1976 (Orange/Black wire). When BCM activates LH DRL relay, voltage level in control circuit should be low. When relay is not activated, voltage level in control circuit should be high.

DTC B0507 will set when BCM detects a low voltage level in circuit No. 1976 (Orange/Black wire) for 2 seconds when it is not energizing LH DRL relay. No driver warning message will be displayed.

DTC B0507 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B0507 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B0507 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK

2. Turn ignition off. Disconnect LH DRL relay from instrument panel electrical center. Turn ignition on. Using a test light connected to ground, probe LH DRL relay BATT terminals at instrument panel electrical center. See Fig. 3

. If test light illuminates, go to next step. If test light does not illuminate, go to

step 13).

3. Turn ignition off. Using a test light connected to battery, probe LH DRL relay CKT 1976 terminal at instrument panel electrical center. See Fig. 3

. If test light illuminates, go to step 10). If test light does not

illuminate, go to next step.

4. Using DVOM, check resistance between LH DRL relay terminals No. 85 and 86. If resistance is 75-105 ohms, go to next step. If resistance is not 75-105 ohms, go to step 12).

Page 33

5. Check for continuity between LH DRL relay terminals No. 85 and 30. If continuity exists, go to step 12).

If continuity does not exist, go to next step.

6. Turn ignition on. Using a test light connected to battery, probe LH DRL relay CKT 1976 terminal at instrument panel electrical center. See Fig. 3

. Using scan tool, command LH DRL relay on and off. If test light toggles on and off as commanded, go to step 8). If test light does not toggle on and off as commanded, go to next step.

7. Turn ignition off. Disconnect BCM Red 16-pin connector C3. Using DVOM, check for continuity between BCM harness connector C3, terminal A7 (Orange/Black wire) and LH DRL relay CKT 1976 terminal at instrument panel electrical center. See Fig. 3

. If continuity exists, go to step 15). If continuity

does not exist, go to step 14).

8. Check for intermittent malfunction in LH DRL circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 16).

9. Ensure ignition is off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Using scan tool, cycle LH DRL relay. If DTC B0507 is current, go to step 15). If DTC B0507 is not current, system is operating properly.

10. Ensure ignition is off. Disconnect BCM Red 16-pin connector C3. Using a test light connected to battery,

probe LH DRL relay CKT 1976 terminal at instrument panel electrical center. See Fig. 3 . If test light illuminates, go to next step. If test light does not illuminate, go to step 15).

11. Repair short to ground in instrument panel electrical center or in circuit No. 1976 (Orange/Black wire) between BCM connector C3 and LH DRL relay. Go to step 16).

12. Replace LH DRL relay. Go to step 16).

13. Repair open in ignition feed circuit to instrument panel electrical center. See POWER DISTRIBUTION under WIRING DIAGRAMS . If a fuse is open, repair short in appropriate circuit. Go to step 16).

14. Repair open in instrument panel electrical center or in circuit No. 1976 (Orange/Black wire) between BCM connector C3 and LH DRL relay. Go to step 16).

15. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

16. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to ground or open in circuit No. 1976 (Orange/Black wire) between BCM and LH DRL relay; poor connections at BCM, instrument panel electrical center or LH DRL relay; or internal open or short in LH DRL relay.

2. If circuit No. 1976 (Orange/Black wire) between BCM and LH DRL relay is shorted to ground, LH DRL will stay on at all times. If circuit No. 1976 (Orange/Black wire) between BCM and LH DRL relay is open, LH DRL will sta

off at all times.

Page 34

Fig. 3: Identifying LH DRL Relay Terminals At Instrument Panel Electrical Center

Courtesy of GENERAL MOTORS CORP.

DTC B0508: LH DRL RELAY CIRCUIT (SHORT TO VOLTAGE OR BCM OPEN)

Description

e high.

Page 35

DTC B0508 will set when BCM detects a high voltage level in circuit No. 1976 (Orange/Black wire) for 2 seconds when it is energizing LH DRL relay. No driver warning message will be displayed.

DTC B0508 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B0508 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B0508 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Turn ignition off. Disconnect LH DRL relay from instrument panel electrical center. Turn ignition on. Using a test light connected to ground, probe LH DRL relay CKT 1976 terminal at instrument panel electrical center. See Fig. 3 . If test light illuminates, go to step 8). If test light does not illuminate, go to next step.

3. Using DVOM, check resistance between LH DRL relay terminals No. 85 and 86. If resistance is 75-105 ohms, go to next step. If resistance is not 75-105 ohms, go to step 11).

4. Turn ignition on. Using a test light connected to battery, probe LH DRL relay CKT 1976 terminal at instrument panel electrical center. See Fig. 3 . Using scan tool, command LH DRL relay on and off. If test light toggles on and off as commanded, go to step 6). If test light does not toggle on and off as commanded, go to next step.

5. Turn ignition off. Disconnect BCM Red 16-pin connector C3. Using DVOM, check for continuity between BCM harness connector C3, terminal A7 (Orange/Black wire) and LH DRL relay CKT 1976 terminal at instrument panel electrical center. See Fig. 3 . If continuity exists, go to step 12). If continuity does not exist, go to step 9).

6. Check for intermittent malfunction in LH DRL circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 13).

7. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Using scan tool, cycle LH DRL relay. If DTC B0508 is current, go to step 12). If DTC B0508 is not current, system is operating properly.

8. Turn ignition off. Disconnect BCM Red 16-pin connector C3. Turn ignition on. Using a test light connected to ground, probe LH DRL relay CKT 1976 terminal at instrument panel electrical center. See

. If test light illuminates, go to step 10). If test light does not illuminate, go to step 12).

Fig. 3

9. Repair open in instrument panel electrical center or in circuit No. 1976 (Orange/Black wire) between BCM connector C3 and LH DRL relay. Go to step 13).

10. Repair short to voltage in instrument panel electrical center or in circuit No. 1976 (Orange/Black wire) between BCM connector C3 and LH DRL relay. Go to step 13).

11. Replace LH DRL relay. Go to step 13).

12. Replace BCM. See REMOVAL & INSTALLATION

. Reprogram BCM. See BCM

PROGRAMMING/RPO CONFIGURATION . Go to next step.

13. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

Page 36

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to voltage in circuit No. 1976 (Orange/Black wire) between BCM and LH DRL relay; poor connections at BCM, instrument panel electrical center or LH DRL relay; or internal short to voltage in LH DRL relay.

2. If circuit No. 1976 (Orange/Black wire) between BCM and LH DRL relay is shorted to voltage or if BCM is open internally, LH DRL will stay off at all times.

DTC B0605: BCM INTERNAL MEMORY MALFUNCTION

Description

BCM calibrations are stored in Electronically Erasable Programmable Read Only Memory (EEPROM). When ignition is first turned on, BCM performs internal tests on EEPROM and determines integrity of its non-volatile memory. BCM then compares this checksum with previously stored checksum. DTC B0605 will set when stored checksum does not match calculated checksum or BCM detects an internal memory malfunction (checksum error). This condition will only occur when ignition is first turned on. No driver warning message will be displayed.

DTC B0605 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B0605 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Replace BCM. See REMOVAL & INSTALLATION. Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

3. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

Since EEPROM cannot be removed from BCM and DTC B0605 is an internal BCM malfunction, BCM must be replaced.

DTC B2403: FRONT FOGLIGHT SWITCH CIRCUIT (SHORT TO VOLTAGE)

Description

Front foglight switch supplies a direct battery input to BCM when switch is pressed. This input allows BCM to detect a front foglight switch ON or OFF request. If BCM detects battery voltage on front foglight circuit No. 192 (Orange wire) when foglights are off, BCM will energize front foglight relay to turn front foglights on. If BCM detects batter

voltage after front foglights ON command, BCM will turn off front foglights. BCM

Page 37

monitors circuit No. 192 to determine how long voltage is applied.

DTC B2403 will set when BCM detects battery voltage on circuit No. 192 (Orange wire) for longer than 60 seconds. No driver warning message will be displayed. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2403 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2403 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Turn ignition off. Disconnect BCM 32-pin connector C2. Turn ignition on. Using a test light connected to ground, probe BCM harness connector C2, terminal D4 (Orange wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 5).

3. Turn ignition off. Disconnect foglight switch connector. Turn ignition on. Using a test light connected to ground, probe BCM harness connector C2, terminal D4 (Orange wire). If test light illuminates, go to step

6). If test light does not illuminate, go to step 7).

4. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Wait 60 seconds and check for DTCs. If DTC B2403 is current, go to step 9). If DTC B2403 is not current, system is operating properly.

5. Check for intermittent malfunction in front foglight switch circuit. See DIAGNOSTIC AIDS. If no problem is found, go to step 4). If problem is found, go to step 8).

6. Repair short to voltage in Orange wire between BCM 32-pin connector C2 and foglight switch. Go to step 10).

7. Replace foglight switch. Go to step 10).

8. Repair intermittent malfunction in front foglight switch circuit. Go to step 10).

9. Replace BCM. See REMOVAL & INSTALLATION. Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

10. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to voltage in circuit No. 192 (Orange wire) between BCM and foglight switch; foglight switch sticking or internally shorted to voltage; or front foglight switch is pressed for longer than 60 seconds.

2. If circuit No. 192 (Orange wire) between BCM and foglight switch is shorted to voltage, front foglights will stay on or off at all times depending on which state they were in when malfunction occurred. If short to voltage occurred when foglights were on, foglights will remain off at all times. If short to voltage occurred when foglights were off, foglights will remain on at all times. BCM will retain this information even if ignition is turned off.

Page 38

DTC B2408: REAR FOGLIGHT SWITCH CIRCUIT (SHORT TO VOLTAGE)

NOTE: This DTC applies only to export vehicles.

Description

Rear foglight switch supplies a direct battery input to BCM when switch is pressed. This input allows BCM to detect a rear foglight switch ON or OFF request. If BCM detects battery voltage on rear foglight circuit No. 187 (Light Blue wire) when rear foglights are off, BCM will energize rear foglight relay to turn rear foglights on. If BCM detects battery voltage after rear foglights ON command, BCM will turn off rear foglights. BCM monitors circuit No. 187 to determine how long voltage is applied.

DTC B2408 will set when BCM detects battery voltage on circuit No. 187 (Light Blue wire) for longer than 60 seconds. No driver warning message will be displayed. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2408 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2408 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Turn ignition off. Disconnect BCM 32-pin connector C2. Turn ignition on. Using a test light connected to ground, probe BCM harness connector C2, terminal D5 (Light Blue wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 5).

3. Turn ignition off. Disconnect foglight switch connector. Turn ignition on. Using a test light connected to ground, probe BCM harness connector C2, terminal D5 (Light Blue wire). If test light illuminates, go to step 6). If test light does not illuminate, go to step 7).

4. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Wait 60 seconds and check for DTCs. If DTC B2408 is current, go to step 9). If DTC B2408 is not current, system is operating properly.

5. Check for intermittent malfunction in rear foglight switch circuit. See DIAGNOSTIC AIDS. If no problem is found, go to step 4). If problem is found, go to step 8).

6. Repair short to voltage in Light Blue wire between BCM 32-pin connector C2 and foglight switch. Go to step 10).

7. Replace foglight switch. Go to step 10).

8. Repair intermittent malfunction in rear foglight switch circuit as necessary. Go to step 10).

9. Replace BCM. See REMOVAL & INSTALLATION. Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

10. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Page 39

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to voltage in circuit No. 187 (Light Blue wire) between BCM and rear foglight switch; rear foglight switch sticking or internally shorted to voltage; or rear foglight switch is pressed for longer than 60 seconds.

2. If circuit No. 187 (Light Blue wire) between BCM and foglight switch is shorted to voltage, rear foglights will stay on or off at all times depending on which state they were in when malfunction occurred. If short to voltage occurred when foglights were on, foglights will remain off at all times. If short to voltage occurred when foglights were off, foglights will remain on at all times. BCM will retain this information even if ignition is turned off.

DTC B2482: BACK-UP LIGHT RELAY CIRCUIT (OPEN OR SHORT TO GROUND)

Description

BCM grounds circuit No. 38 (Dark Blue wire) to energize back-up light relay, which will turn back-up lights on. This allows back-up lights to be used in Underhood Theft Deterrent (UTD) and approach lighting functions.

BCM monitors voltage level on circuit No. 38 (Dark Blue wire). When BCM activates back-up light relay, voltage level in control circuit should be low. When relay is not activated, voltage level in control circuit should be high.

DTC B2482 will set when BCM detects a low voltage level in circuit No. 38 (Dark Blue wire) for 2 seconds when it is not energizing back-up light relay. No driver warning message will be displayed.

DTC B2482 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2482 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2482 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK

2. Turn ignition off. Disconnect back-up light relay from underhood electrical center. Turn ignition on. Using a test light connected to ground, probe back-up light relay BATT terminals at underhood electrical center. See Fig. 4

. If test light illuminates, go to next step. If test light does not illuminate, go to step 14).

3. Turn ignition off. Using a test light connected to battery, probe back-up light relay CKT 38 terminal at underhood electrical center. See Fig. 4 . If test light illuminates, go to step 11) . If test light does not illuminate, go to next step.

4. Using DVOM, check resistance between back-up light relay terminals No. 85 and 86. If resistance is 75105 ohms, go to next step. If resistance is not 75-105 ohms, go to step 13).

5. Check for continuity between back-up light relay terminals No. 85 and 87. If continuity exists, go to step

13). If continuity does not exist, go to next step.

Page 40

6. Check for continuity between back-up light relay terminals No. 85 and 30. If continuity exists, go to step

13). If continuity does not exist, go to next step.

7. Turn ignition on. Using a test light connected to battery, probe back-up light relay CKT 38 terminal at underhood electrical center. See Fig. 4

. Using scan tool, command back-up light re lay on and off. If test light toggles on and off as commanded, go to step 9). If test light does not toggle on and off as commanded, go to next step.

8. Turn ignition off. Disconnect BCM 32-pin connector C2. Using DVOM, check for continuity between BCM harness connector C2, terminal C1 (Dark Blue wire) and back-up light relay CKT 38 terminal at underhood electrical center. See Fig. 4

. If continuity exists, go to step 16). If continuity does not exist, go

to step 15).

9. Check for intermittent malfunction in back-up light circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 17).

10. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Using scan tool, cycle back-up light relay. If DTC B2482 is current, go to step 16). If DTC B2482 is not current, system is operating properly.

11. Ensure ignition is off. Disconnect BCM 32-pin connector C2. Using a test light connected to battery, probe back-up light relay CKT 38 terminal at underhood electrical center. See Fig. 4 . If test light illuminates, go to next step. If test light does not illuminate, go to step 16).

12. Repair short to ground in underhood electrical center or in circuit No. 38 (Dark Blue wire) between BCM connector C2 and back-up light relay. Go to step 17).

13. Replace back-up light relay. Go to step 17).

14. Repair open in ignition feed circuit to underhood electrical center. See POWER DISTRIBUTION under WIRING DIAGRAMS . If a fuse is open, repair short in appropriate circuit. Go to step 17).

15. Repair open in underhood electrical center or in circuit No. 38 (Dark Blue wire) between BCM connector C2 and back-up light relay. Go to step 17).

16. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

17. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to ground or open in circuit No. 38 (Dark Blue wire) between BCM and back-up light relay; poor connections at BCM, underhood electrical center, or back-up light relay; or internal open or short in back-up light relay.

2. If circuit No. 38 (Dark Blue wire) between BCM and back-up light relay is shorted to ground, back-up lights will stay on at all times. If circuit No. 38 (Dark Blue wire) between BCM and back-up light relay is open, bac

-up lights will stay off at all times.

Page 41

Fig. 4: Identifying Back-Up Light Relay Terminals At Underhood Electrical Center

Courtesy of GENERAL MOTORS CORP.

DTC B2483: BACK-UP LIGHT RELAY CIRCUIT (SHORT TO VOLTAGE OR BCM OPEN)

Description

e high.

Page 42

DTC B2483 will set when BCM detects a high voltage level in circuit No. 38 (Dark Blue wire) for 2 seconds

when it is energizing back-up light relay. No driver warning message will be displayed.

DTC B2483 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2483 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2483 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Turn ignition off. Disconnect back-up light relay from underhood electrical center. Turn ignition on. Using a test light connected to ground, probe back-up light relay CKT 38 terminal at underhood electrical center. See Fig. 4 . If test light illuminates, go to step 10). If test light does not illuminate, go to next step.

3. Using DVOM, check resistance between back-up light relay terminals No. 85 and 86. If resistance is 75105 ohms, go to next step. If resistance is not 75-105 ohms, go to step 13).

4. Check for continuity between back-up light relay terminals No. 85 and 87. If continuity exists, go to step

13). If continuity does not exist, go to next step.

5. Check for continuity between back-up light relay terminals No. 85 and 30. If continuity exists, go to step

13). If continuity does not exist, go to next step.

6. Turn ignition on. Using a test light connected to battery, probe back-up light relay CKT 38 terminal at underhood electrical center. See Fig. 4 . Using scan tool, command back-up light re lay on and off. If test light toggles on and off as commanded, go to step 8). If test light does not toggle on and off as commanded, go to next step.

7. Turn ignition off. Disconnect BCM 32-pin connector C2. Using DVOM, check for continuity between BCM harness connector C2, terminal C1 (Dark Blue wire) and back-up light relay CKT 38 terminal at underhood electrical center. See Fig. 4 . If continuity exists, go to step 14). If continuity does not exist, go to step 11).

8. Check for intermittent malfunction in back-up light circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 15).

9. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Using scan tool, cycle back-up light relay. If DTC B2483 is current, go to step 14). If DTC B2483 is not current, system is operating properly.

10. Turn ignition off. Disconnect BCM 32-pin connector C2. Turn ignition on. Using a test light connected to

ground, probe back-up light relay CKT 38 terminal at underhood electrical center. See Fig. 4

. If test light

illuminates, go to step 12). If test light does not illuminate, go to step 14).

11. Repair open in underhood electrical center or in circuit No. 38 (Dark Blue wire) between BCM connector C2 and back-up light relay. Go to step 15).

12. Repair short to voltage in underhood electrical center or in circuit No. 38 (Dark Blue wire) between BCM connector C2 and back-up light relay. Go to step 15).

13. Replace bac

-up light relay. Go to step 15).

Page 43

14. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

15. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to voltage in circuit No. 38 (Dark Blue wire) between BCM and back-up light relay; poor connections at BCM, underhood electrical center, or back-up light relay; or internal short to voltage in back-up light relay.

2. If circuit No. 38 (Dark Blue wire) between BCM and back-up light relay is shorted to voltage or if BCM is open internally, back-up light will stay off at all times.

DTC B2527: HORN RELAY CIRCUIT (OPEN OR SHORT TO GROUND)

Description

BCM grounds circuit No. 28 (Black wire) to energize horn relay, which will turn horns on. This allows horns to be used in Underhood Theft Deterrent (UTD) functions.

BCM monitors voltage level on circuit No. 28 (Black wire). When BCM activates horn relay, voltage level in control circuit should be low. When relay is not activated, voltage level in control circuit should be high.

DTC B2527 will set when BCM detects a low voltage level in circuit No. 28 (Black wire) for 2 seconds when it is not energizing horn relay. No driver warning message will be displayed.

DTC B2527 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2527 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2527 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK

2. Turn ignition off. Disconnect horn relay from underhood electrical center. Turn ignition on. Using a test light connected to ground, probe horn relay BATT terminals at underhood electrical center. See Fig. 5 . If test light illuminates, go to next step. If test light does not illuminate, go to step 16).

3. Turn ignition off. Using a test light connected to battery, probe horn relay CKT 28 terminal at underhood electrical center. See Fig. 5

. If test light illuminates, go to step 11). If test light does not illuminate, go to

next step.

4. Using DVOM, check resistance between horn relay terminals No. 85 and 86. If resistance is 75-105 ohms, go to next step. If resistance is not 75-105 ohms, go to step 14).

Page 44

5. Check for continuity between horn relay terminals No. 85 and 87. If continuity exists, go to step 14). If

continuity does not exist, go to next step.

6. Check for continuity between horn relay terminals No. 85 and 30. If continuity exists, go to step 14). If continuity does not exist, go to next step.

7. Turn ignition on. Using a test light connected to battery, probe horn relay CKT 28 terminal at underhood electrical center. See Fig. 5 . Using scan tool, command horn relay on and off. If test light toggles on and off as commanded, go to step 9). If test light does not toggle on and off as commanded, go to next step.

8. Turn ignition off. Disconnect BCM 24-pin connector C1. Using DVOM, check for continuity between BCM harness connector C1, terminal B10 (Black wire) and horn relay CKT 28 terminal at underhood electrical center. See Fig. 5 . If continuity exists, go to step 18). If continuity does not exist, go to step

17).

9. Check for intermittent malfunction in horn circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 19).

10. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Using scan tool, cycle horn relay. If DTC B2527 is current, go to step 18). If DTC B2527 is not current, system is operating properly.

11. Ensure ignition is off. Disconnect BCM 24-pin connector C1. Using a test light connected to battery, probe horn relay CKT 28 terminal at underhood electrical center. See Fig. 5 . If test light illuminates, go to next step. If test light does not illuminate, go to step 18).

12. Disconnect steering column C221 connector. Using a test light connected to battery, probe horn relay CKT 28 terminal at underhood electrical center. See Fig. 5 . If test light illuminates, go to next step. If test light does not illuminate, go to step 15).

13. Repair short to ground in underhood electrical center or in circuit No. 28 (Black wire) between BCM connector C1 and horn relay. Go to step 19).

14. Replace horn relay. Go to step 19).

15. Repair short to ground in steering column. Go to step 19).

16. Repair open in ignition feed circuit to underhood electrical center. See POWER DISTRIBUTION under

WIRING DIAGRAMS

. If a fuse is open, repair short in appropriate circuit. Go to step 19).

17. Repair open in underhood electrical center or in circuit No. 28 (Black wire) between BCM connector C1 and horn relay. Go to step 19).

18. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

19. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. Horn relay may be installed in 2 directions in underhood electrical center, and still function properly. The following conditions may cause an intermittent: Intermittent short to ground or open in circuit No. 28 (Black wire) between BCM and horn relay; short to ground in horn pad; poor connections at BCM, underhood electrical center or horn relay; or internal open or short to ground in horn relay.

2. If circuit No. 28 (Black wire) between BCM and horn relay is shorted to ground, horn will stay on at all times. If circuit No. 28 (Black wire) between BCM and horn rela

is open, horn will stay off at all times.

Page 45

Fig. 5: Horn Relay Terminals At Underhood Electrical Center Courtesy of GENERAL MOTORS CORP.

DTC B2528: HORN RELAY CIRCUIT (SHORT TO VOLTAGE OR BCM OPEN)

Description

BCM grounds circuit No. 28 (Black wire) to energize horn relay, which will turn horns on. This allows horns to be used in Underhood Theft Deterrent (UTD) functions.

DTC B2528 will set when BCM detects a high voltage level in circuit No. 28 (Black wire) for 2 seconds when

Page 46

it is energizing horn relay. No driver warning message will be displayed.

DTC B2528 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2528 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2528 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Turn ignition off. Disconnect horn relay from underhood electrical center. Turn ignition on. Using a test light connected to ground, probe horn relay CKT 28 terminal at underhood electrical center. See Fig. 5 . If test light illuminates, go to step 10). If test light does not illuminate, go to next step.

3. Using DVOM, check resistance between horn relay terminals No. 85 and 86. If resistance is 75-105 ohms, go to next step. If resistance is not 75-105 ohms, go to step 15).

4. Check for continuity between horn relay terminals No. 85 and 87. If continuity exists, go to step 15). If continuity does not exist, go to next step.

5. Check for continuity between horn relay terminals No. 85 and 30. If continuity exists, go to step 15). If continuity does not exist, go to next step.

6. Turn ignition on. Using a test light connected to battery, probe horn relay CKT 28 terminal at underhood electrical center. See Fig. 5 . Using scan tool, command horn relay on and off. If test light toggles on and off as commanded, go to step 8). If test light does not toggle on and off as commanded, go to next step.

7. Turn ignition off. Disconnect BCM 24-pin connector C1. Using DVOM, check for continuity between BCM harness connector C1, terminal B10 (Black wire) and horn relay CKT 28 terminal at underhood electrical center. See Fig. 5 . If continuity exists, go to step 16). If continuity does not exist, go to step

12).

8. Check for intermittent malfunction in horn circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 17).

9. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Using scan tool, cycle horn relay. If DTC B2528 is current, go to step 16). If DTC B2528 is not current, system is operating properly.

10. Turn ignition off. Disconnect BCM 24-pin connector C1. Turn ignition on. Using a test light connected to

ground, probe horn relay CKT 28 terminal at underhood electrical center. See Fig. 5

. If test light

illuminates, go to next step. If test light does not illuminate, go to step 16).

11. Disconnect steering column C221 connector. Using a test light connected to ground, probe horn relay

CKT 28 terminal at underhood electrical center. See Fig. 5

. If test light illuminates, go to step 13). If test

light does not illuminate, go to step 14).

12. Repair open in underhood electrical center or in circuit No. 28 (Black wire) between BCM connector C1 and horn relay. Go to step 17).

13. Repair short to voltage in underhood electrical center or in circuit No. 28 (Black wire) between BCM connector C1 and horn relay. Go to step 17).

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14. Repair short to voltage in steering column. Go to step 17).

15. Replace horn relay. Go to step 17).

16. Replace BCM. See REMOVAL & INSTALLATION

. Reprogram BCM. See BCM

PROGRAMMING/RPO CONFIGURATION . Go to next step.

17. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. Horn relay may be installed in 2 directions in underhood electrical center, and still function properly. The following conditions may cause an intermittent: Intermittent short to voltage in circuit No. 28 (Black wire) between BCM and horn relay; poor connections at BCM, underhood electrical center or horn relay; or internal short to voltage in horn relay.

2. If circuit No. 28 (Black wire) between BCM and horn relay is shorted to voltage or if BCM is open internally, horn will stay off at all times.

DTC B2573: HATCH RELEASE SWITCH CIRCUIT (SHORT TO VOLTAGE)

Description

Hatch release switch supplies a direct battery input to BCM when switch is pressed. This input allows BCM to detect a hatch release request. If BCM detects battery voltage on hatch release circuit No. 1576 (Black wire), BCM will energize hatch release relay. BCM monitors circuit No. 1576 to determine how long voltage is applied.

DTC B2573 will set when BCM detects battery voltage on circuit No. 1576 (Black wire) for longer than 60 seconds. No driver warning message will be displayed. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2573 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2573 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK

2. Turn ignition off. Disconnect BCM 32-pin connector C2. Turn ignition on. Using a test light connected to ground, probe BCM harness connector C2, terminal D9 (Black wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 5).

3. Turn ignition off. Disconnect hatch release switch. Turn ignition on. Using a test light connected to ground, probe BCM harness connector C2, terminal D9 (Black wire). If test light illuminates, go to step

6). If test light does not illuminate, go to step 7).

4. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Wait 60 seconds and check for DTCs. If DTC B2573 is current, go to step 9). If DTC B2573 is not current, system

Page 48

is operating properly.

5. Check for intermittent malfunction in hatch release switch circuit. See DIAGNOSTIC AIDS. If no problem is found, go to step 4). If problem is found, go to step 8).

6. Repair short to voltage in circuit No. 1576 (Black wire) between BCM connector C2 and hatch release switch. Go to step 10).

7. Replace hatch release switch. See POWER HATCH & FUEL DOOR RELEASE article. Go to step 10).

8. Repair intermittent malfunction in hatch release switch circuit. Go to step 10).

9. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

10. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to voltage in circuit No. 1576 (Black wire) between BCM and hatch release switch; hatch release switch sticking or internally shorted to voltage; or hatch release switch is pressed for longer than 60 seconds.

2. If short to voltage occurs in circuit No. 1576 (Black wire) between BCM and hatch release switch when ignition is on, rear hatch switch will release once and then remain inoperative. If short to voltage occurred when ignition is off, rear hatch switch will release when ignition is turned on and then remain inoperative. BCM will retain information of last transition, and will not release rear hatch again until it received a change from hatch release switch.

DTC B2578: RF TURN SIGNAL MONITOR CIRCUIT (SHORT TO VOLTAGE)

Description

BCM monitors RF turn signal circuit to determine status of turn signal switch. When BCM detects an oscillating voltage on circuit No. 15 (Dark Blue wire), BCM interprets this as a request from turn signal switch to turn RF turn signal on. The BCM then stops energizing RH DRL relay, which disables RF turn signal light from DRL circuit, so that RF turn signal light will now flash. The BCM monitors circuit No. 15 to determine how long voltage is applied.

DTC B2578 will set when BCM detects continuous battery voltage on circuit No. 15 (Dark Blue wire) for longer than 5 seconds. No driver warning message will be displayed.

DTC B2578 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2578 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2578 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

NOTE: To identify wire colors for lighting system, see WIRING DIAGRAMS

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Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK

2. Using scan tool, check for DTC B2583. If DTC B2583 exists, go to step 14). If DTC B2583 does not exist, go to next step.

3. Turn ignition off. Disconnect RH DRL relay from instrument panel electrical center. Turn ignition on. Turn turn signals off. Using a test light connected to ground, probe RH DRL relay CKT 15 at instrument panel electrical center. See Fig. 2 . If test light illuminates, go to step 6). If test light does not illuminate, go to next step.

4. Using a test light connected to ground, probe RH DRL relay CKT 1315 at instrument panel electrical center. See Fig. 2 . If test light illuminates, go to step 13). If test light does not illuminate, go to next step.

5. Using DVOM, check for continuity between RH DRL relay terminals No. 87 and 87A. If continuity exists, go to step 17). If continuity does not exist, go to step 9).

6. Turn ignition off. Disconnect hazard warning switch connector. Turn ignition on. Using a test light connected to ground, probe RH DRL relay CKT 15 at instrument panel electrical center. See Fig. 2 . If test light illuminates, go to next step. If test light does not illuminate, go to step 16).

7. Turn ignition off. Disconnect turn signal switch connector C211. Turn ignition on. Using a test light connected to ground, probe RH DRL relay CKT 15 at instrument panel electrical center. See Fig. 2 . If test light illuminates, go to next step. If test light does not illuminate, go to step 15).

8. Turn ignition off. Disconnect IPC connector. Turn ignition on. Using a test light connected to ground, probe RH DRL relay CKT 15 at instrument panel electrical center. See Fig. 2 . If test light illuminates, go to step 11). If test light does not illuminate, go to step 12).

9. Check for the following intermittent faults:

z A short to voltage in circuit No. 15 (Dark Blue wire), circuit No. 16 (Purple wire) or circuit No.

1315 (Dark Blue/White wire).

z An internal short in RH DRL relay. z An internal short in turn signal switch. z An internal short in hazard warning switch. z A short at IPC terminal A16 (Dark Blue wire).

If no problem was found, go to next step. If problem is found, repair as necessary. Go to step 19).

10. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Wait 5 seconds and check for DTCs. If DTC B2578 is current, go to step 18). If DTC B2578 is not current, system is operating properly.

11. Repair short to voltage in circuit No. 15 (Dark Blue wire) between BCM connector C2 and instrument panel electrical center connector C2. Go to step 19).

12. Repair short to voltage at IPC connector terminal A16 (Dark Blue wire). Go to step 19).

13. Repair short to voltage in circuit No. 1315 (Dark Blue/White wire) between instrument panel electrical center connector C2 and RF turn signal light. Go to step 19).

14. Check for short to voltage in circuit No. 16 (Purple wire) between hazard warning switch and turn signal switch. If no problem is found, go to step 16). If problem is found, repair as necessary. Go to step 19).

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15. Replace turn signal switch. See STEERING COLUMN SWITCHES article. Go to step 19).

16. Replace hazard warning switch. Go to step 19).

17. Replace RH DRL relay. Go to step 19).

18. Replace BCM. See REMOVAL & INSTALLATION

. Reprogram BCM. See BCM

PROGRAMMING/RPO CONFIGURATION . Go to next step.

19. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to voltage in circuit No. 15 (Dark Blue wire), circuit No. 16 (Purple wire) or circuit No. 1315 (Dark Blue/White wire);or turn signal switch or hazard warning switch sticking or internally shorted.

2. BCM needs to detect voltage oscillation on circuit No. 15 (Dark Blue wire) in order to deactivate RF turn signal relay. If BCM detects continuous battery voltage, it is interpreted as a short to voltage. BCM will continue normal DRL operation, and RF turn signal will be inoperative.

DTC B2583: LF TURN SIGNAL MONITOR CIRCUIT (SHORT TO VOLTAGE)

Description

BCM monitors LF turn signal circuit to determine status of turn signal switch. When BCM detects an oscillating voltage on circuit No. 14 (Light Blue wire), BCM interprets this as a request from turn signal switch to turn LF turn signal on. The BCM then stops energizing LH DRL relay, which disables LF turn signal light from DRL circuit, so that LF turn signal light will now flash. The BCM monitors circuit No. 14 to determine how long voltage is applied.

DTC B2583 will set when BCM detects continuous battery voltage on circuit No. 14 (Light Blue wire) for longer than 5 seconds. No driver warning message will be displayed.

DTC B2583 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2583 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2583 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

NOTE: To identify wire colors for lighting system, see WIRING DIAGRAMS

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK

2. Using scan tool, check for DTC B2578. If DTC B2578 exists, go to step 14). If DTC B2578 does not exist, go to next step.

Page 51

3. Turn ignition off. Disconnect LH DRL relay from instrument panel electrical center. Turn ignition on. Turn turn signals off. Using a test light connected to ground, probe LH DRL relay CKT 14 at instrument panel electrical center. See Fig. 3

. If test light illuminates, go to step 6). If test light does not illuminate,

go to next step.

4. Using a test light connected to ground, probe LH DRL relay CKT 1314 at instrument panel electrical center. See Fig. 3 . If test light illuminates, go to step 13). If test light does not illuminate, go to next step.

5. Using DVOM, check for continuity between LH DRL relay terminals No. 87 and 87A. If continuity exists, go to step 17). If continuity does not exist, go to step 9).

6. Turn ignition off. Disconnect hazard warning switch connector. Turn ignition on. Using a test light connected to ground, probe LH DRL relay CKT 14 at instrument panel electrical center. See Fig. 3

. If

test light illuminates, go to next step. If test light does not illuminate, go to step 16).

7. Turn ignition off. Disconnect turn signal switch connector C211. Turn ignition on. Using a test light connected to ground, probe LH DRL relay CKT 14 at instrument panel electrical center. See Fig. 3 . If test light illuminates, go to next step. If test light does not illuminate, go to step 15).

8. Turn ignition off. Disconnect IPC connector. Turn ignition on. Using a test light connected to ground, probe LH DRL relay CKT 14 at instrument panel electrical center. See Fig. 3 . If test light illuminates, go to step 11). If test light does not illuminate, go to step 12).

9. Check for the following intermittent faults:

z A short to voltage in circuit No. 14 (Light Blue wire), circuit No. 16 (Purple wire) or circuit No.

1314 (Light Blue/White wire).

z An internal short in LH DRL relay. z An internal short in turn signal switch. z An internal short in hazard warning switch. z A short at IPC terminal A15 (Light Blue wire).

If no problem was found, go to next step. If problem is found, repair as necessary. Go to step 19).

10. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Wait 5 seconds and check for DTCs. If DTC B2583 is current, go to step 18). If DTC B2583 is not current, system is operating properly.

11. Repair short to voltage in circuit No. 14 (Light Blue wire) between BCM connector C2 and instrument panel electrical center connector C1. Go to step 19).

12. Repair short to voltage at IPC connector terminal A15 (Light Blue wire). Go to step 19).

13. Repair short to voltage in circuit No. 1314 (Light Blue/White wire) between instrument panel electrical center connector C1 and LF turn signal light. Go to step 19).

15. Replace turn signal switch. See STEERING COLUMN SWITCHES article. Go to step 19).

16. Replace hazard warning switch. Go to step 19).

17. Replace LH DRL relay. Go to step 19).

18. Replace BCM. See REMOVAL & INSTALLATION

. Reprogram BCM. See BCM

PROGRAMMING/RPO CONFIGURATION . Go to next step.

Page 52

19. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to voltage in circuit No. 14 (Light Blue wire), circuit No. 16 (Purple wire) or circuit No. 1314 (Light Blue/White wire);or turn signal switch or hazard warning switch sticking or internally shorted.

2. BCM needs to detect voltage oscillation on circuit No. 14 (Light Blue wire) in order to deactivate LF turn signal relay. If BCM detects continuous battery voltage, it is interpreted as a short to voltage. BCM will continue normal DRL operation, and LF turn signal will be inoperative.

DTC B2587: COLUMN LOCK/UNLOCK DRIVE "A" (OPEN OR SHORT TO GROUND)

Description

BCM provides steering column control function that allows steering column to be electronically locked or unlocked. BCM can supply a ground or battery output on column lock/unlock drive "A" circuit depending on desired steering column lock motor position. BCM controls motor position based on input information, which includes: Ignition position; key-in-ignition status; key-out-of-ignition status; system voltage; and information sent from steering column lock feedback switch, PASS-Key(R) system and PCM.

BCM uses steering column lock feedback switch to monitor motor position, and to determine if commanded

osition was accomplished. BCM continuously monitors column lock/unlock drive "A" circuit No. 1603

(Orange wire).

DTC B2587 will set when BCM detects an internal malfunction (short to ground or open) in column lock/unlock drive "A" circuit No. 1603 (Orange wire) or an open in BCM voltage supply circuit No. 2540 (Orange wire) for 100 milliseconds. IPC will display SERVICE COLUMN LOCK message. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2587 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2587 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK

2. Check BCM fuse No. 23 (10-amp), located in instrument panel electrical center. See Fig. 1

. If fuse is

open, go to next step. If fuse is okay, go to step 10).

3. Turn ignition off. Disconnect BCM Red 16-pin connector C3. Using a test light connected to battery, probe BCM harness connector C3, terminal A4 (Orange wire). If test light illuminates, go to step 11). If test light does not illuminate, go to next step.

4. Disconnect steering column C207 connector. Using a test light connected to battery, probe BCM harness connector C3, terminal A8 (Orange wire). If test light illuminates, go to step 12). If test light does not

Page 53

illuminate, go to next step.

5. Using a test light connected to battery, probe BCM harness connector C3, terminal A6 (Purple wire). If test light illuminates, go to step 12). If test light does not illuminate, go to next step.

6. Using DVOM, check for continuity between BCM harness connector C3, terminals A6 (Purple wire) and A8 (Orange wire). If continuity exists, go to step 13). If continuity does not exist, go to next step.

7. Replace BCM fuse No. 23. Reconnect BCM connector C3. Remove key from ignition switch. Connect a test light between steering column connector C207 (harness side) terminals "C" (Purple wire) and "D" (Orange wire). Using scan tool, cycle steering column lock/unlock motor. If test light illuminates in both positions, go to step 14). If test light does not illuminate in both positions, go to step 15).

8. Check for intermittent malfunction in steering column circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 16).

9. Turn ignition off. Remove BCM fuse No. 25 (10-amp) from instrument panel electrical center for 15 seconds to clear BCM steering column fail enable mode. See Fig. 1 . Turn ignition on. Clear DTCs. Check for DTCs. If DTC B2587 is current, go to step 15). If DTC B2587 is not current, go to step 16).

10. Check for open in circuit No. 2540 (Orange wire) between BCM connector C3 and instrument panel electrical center connector C1. If no problem is found, go to step 8). If problem is found, repair as necessary. Go to step 16).

11. Repair short to ground in instrument panel electrical center or in circuit No. 2540 (Orange wire) between BCM connector C3 and instrument panel electrical center connector C1. Go to step 16).

12. Repair short to ground in circuit No. 1603 (Orange wire) or No. 1604 (Purple wire) between BCM connector C3 and steering wheel lock. Go to step 16).

13. Repair short between circuits No. 1603 (Orange wire) and No. 1604 (Purple wire) between BCM connector C3 and steering wheel lock. Go to step 16).

14. Replace steering wheel lock/unlock motor (located in steering wheel lock on instrument panel, right of steering column). Go to step 16).

15. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

16. Turn ignition off. Remove BCM fuse No. 25 (10-amp) from instrument panel electrical center for 15 seconds to clear BCM steering column fail enable mode. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent open in circuit No. 2540 (Orange wire), or circuits No. 1603 (Orange wire) and No. 1604 (Purple wire) are shorted together or to ground.

2. A short to ground in circuit No. 2540 (Orange wire) between BCM connector C3 and instrument panel electrical center connector C1 will cause BCM fuse No. 23 to open. If BCM is unable to supply voltage to steering column lock/unlock motor through circuit No. 2540 (Orange wire), DTC B2587 will set.

3. Disconnecting steering column connector C207 when ignition is on will cause BCM to enter a fail enable standby mode. Steering column will remain inoperative until fail enable standby mode is cleared. Remove BCM fuse No. 25 for 15 seconds to clear fail enable standby mode.

DTC B2588: COLUMN LOCK/UNLOCK DRIVE "A" (OPEN OR SHORT TO VOLTAGE)

Page 54

Description

BCM uses steering column lock feedback switch to monitor motor position, and to determine if commanded

osition was accomplished. BCM continuously monitors column lock/unlock drive "A" circuit No. 1603

(Orange wire).

DTC B2588 will set when BCM detects an internal malfunction (short to voltage or open) in column lock/unlock drive "A" circuit No. 1603 (Orange wire) or an open in BCM ground circuit No. 150 (Black wire) for 100 milliseconds. IPC will display SERVICE COLUMN LOCK message. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2588 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2588 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Turn ignition off. Disconnect BCM Red 16-pin connector C3. Using a test light connected to battery, probe BCM harness connector C3, terminal A2 (Black wire). If test light illuminates, go to step 4). If test light does not illuminate, go to next step.

3. Repair open in Black wire between BCM connector C3 and splice pack No. 202 (instrument panel harness, at base of right "A" pillar). Go to step 7).

4. Check for intermittent malfunction at BCM connector C3, terminal A2 (Black wire). See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 7).

5. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Check for DTCs. If DTC B2588 is current, go to next step. If DTC B2588 is not current, system is operating properly.

6. Replace BCM. See REMOVAL & INSTALLATION

. Reprogram BCM. See BCM

PROGRAMMING/RPO CONFIGURATION . Go to next step.

7. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

If BCM is unable to ground steering column lock/unlock motor using circuit No. 150 (Black wire), it will set DTC B2588. Disconnecting steering column connector C207 when ignition is on will cause BCM to enter a fail enable mode. Steering column will remain inoperative until fail enable standby mode is cleared. Remove BCM

Page 55

fuse No. 25 for 15 seconds to clear fail enable standby mode.

DTC B2592: COLUMN LOCK/UNLOCK DRIVE "B" (OPEN OR SHORT TO GROUND)

Description

BCM provides steering column control function that allows steering column to be electronically locked or unlocked. BCM can supply a ground or battery output on column lock/unlock drive "B" circuit depending on desired steering column lock motor position. BCM controls motor position based on input information, which includes: Ignition position; key-in-ignition status; key-out-of-ignition status; system voltage; and information sent from steering column lock feedback switch, PASS-Key(R) system and PCM.

BCM uses steering column lock feedback switch to monitor motor position, and to determine if commanded

osition was accomplished. BCM continuously monitors column lock/unlock drive "B" circuit No. 1604 (Purple

wire).

DTC B2592 will set when BCM detects an internal malfunction (short to ground or open) in column lock/unlock drive "B" circuit No. 1604 (Purple wire) or an open in BCM voltage supply circuit No. 2540 (Orange wire) for 100 milliseconds. IPC will display SERVICE COLUMN LOCK message. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2592 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2592 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Check BCM fuse No. 23 (10-amp), located in instrument panel electrical center. See Fig. 1

. If fuse is

open, go to next step. If fuse is okay, go to step 10).

5. Using a test light connected to battery, probe BCM harness connector C3, terminal A6 (Purple wire). If test light illuminates, go to step 12). If test light does not illuminate, go to next step.

oth positions, go to step 14). If test light does not illuminate in both positions, go to step 15).

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8. Check for intermittent malfunction in steering column circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 16).

9. Turn ignition off. Remove BCM fuse No. 25 (10-amp) from instrument panel electrical center for 15 seconds to clear BCM steering column fail enable mode. Turn ignition on. Clear DTCs. Check for DTCs. If DTC B2592 is current, go to step 15). If DTC B2592 is not current, go to step 16).

11. Repair short to ground in instrument panel electrical center or in circuit No. 2540 (Orange wire) between BCM connector C3 and instrument panel electrical center connector C1. Go to step 16).

12. Repair short to ground in circuit No. 1603 (Orange wire) or No. 1604 (Purple wire) between BCM connector C3 and steering wheel lock. Go to step 16).

13. Repair short between circuits No. 1603 (Orange wire) and No. 1604 (Purple wire) between BCM connector C3 and steering wheel lock. Go to step 16).

14. Replace steering wheel lock/unlock motor (located in steering wheel lock on instrument panel, right of steering column). Go to step 16).

15. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

Diagnostic Aids

DTC B2593: COLUMN LOCK/UNLOCK DRIVE "B" (OPEN OR SHORT TO VOLTAGE)

Description

BCM provides steering column control function that allows steering column to be electronically locked or unlocked. BCM can supply a ground or battery output on column lock/unlock drive "B" circuit depending on desired steering column lock motor position. BCM controls motor position based on input information, which includes: Ignition position; key-in-ignition status; key-out-of-ignition status; system voltage; and information sent from steering column lock feedback switch, PASS-Key(R) system and PCM.

BCM uses steering column lock feedback switch to monitor motor position, and to determine if commanded

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osition was accomplished. BCM continuously monitors column lock/unlock drive "B" circuit No. 1604

(Orange wire).

DTC B2593 will set when BCM detects an internal malfunction (short to voltage or open) in column lock/unlock drive "B" circuit No. 1604 (Orange wire) or an open in BCM ground circuit No. 150 (Black wire) for 100 milliseconds. IPC will display SERVICE COLUMN LOCK message. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2593 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2593 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

3. Repair open in Black wire between BCM connector C3 and splice pack No. 202 (instrument panel harness, at base of right "A" pillar). Go to step 7).

6. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

7. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

If BCM is unable to ground steering column lock/unlock motor using circuit No. 150 (Black wire), it will set DTC B2593. Disconnecting steering column connector C207 when ignition is on will cause BCM to enter a fail enable standby mode. Steering column will remain inoperative until fail enable standby mode is cleared. Remove BCM fuse No. 25 for 15 seconds to clear fail enable standby mode.

DTC B2597: TCS SWITCH CIRCUIT (SHORT TO GROUND)

Description

Traction Control System (TCS) switch circuit provides a ground input to BCM when switch is pressed. If BCM detects a ground on circuit No. 1571 (Brown/White wire) when TCS is off, BCM will send signal on serial data line to Electronic Brake Traction Control Module (EBTCM) to turn on TCS. If BCM detects a ground when

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TCS is activated, BCM will send another signal to EBTCM to turn off TCS. BCM monitors TCS switch circuit

to determine how long a ground has been applied. DTC B2597 will set when BCM detects a ground on circuit

o. 1571 (Brown/White wire) for longer than 60 seconds. No driver warning message will be displayed. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2597 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2597 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was

not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK

2. Turn ignition off. Disconnect BCM 32-pin connector C2. Using a test light connected to battery, probe BCM harness connector C2, terminal D15 (Brown/White wire). If test light illuminates, go to next step. If test light does not illuminate, go to step 5).

3. Ensure ignition is off. Disconnect TCS switch. Using a test light connected to battery, probe BCM harness connector C2, terminal D15 (Brown/White wire). If test light illuminates, go to step 6). If test light does not illuminate, go to step 7).

4. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Wait 60 seconds and check for DTCs. If DTC B2597 is current, go to step 9). If DTC B2597 is not current, system is operating properly.

5. Check for intermittent malfunction in TCS switch circuit. See DIAGNOSTIC AIDS. If no problem is found, go to step 4). If problem is found, go to step 8).

6. Repair short to ground in Brown/White wire between BCM 32-pin connector C2 and TCS switch. Go to step 10).

7. Replace TCS switch. Go to step 10).

8. Repair intermittent malfunction in TCS switch circuit. Go to step 10).

9. Replace BCM. See REMOVAL & INSTALLATION

. Reprogram BCM. See BCM

PROGRAMMING/RPO CONFIGURATION . Go to next step.

10. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to ground in circuit No. 1571 (Brown/White wire) between BCM and TCS switch; TCS switch sticking or internally shorted to ground; or TCS switch is pressed for longer than 60 seconds.

2. If circuit No. 1571 (Brown/White wire) between BCM and TCS switch is shorted to ground, TCS will stay on or off at all times depending on which state it was in when malfunction occurred. If short to ground occurred when TCS was on, TCS will remain off at all times. If short to ground occurred when TCS was off, TCS will remain on at all times. BCM will retain this information even if ignition is turned off.

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DTC B2721: PASS-KEY(R) DETECTION CIRCUIT (OUT OF RANGE)

Description

Insertion of PASS-Key(R) into ignition lock cylinder completes PASS-Key(R) circuit. Contacts in ignition lock cylinder mate with resistor pellet contacts in PASS-Key(R). BCM compares resistance value of key pellet to valid resistance programmed into BCM. When proper resistance value is read, BCM will allow theft deterrent relay to energize, steering column to unlock, and will send a message through serial data line to PCM to allow fuel enable processing to occur.

DTC B2721 will set when resistance level at BCM's PASS-Key(R) input circuit is one of 14 valid (but incorrect) resistance ranges for one second, signaling an invalid PASS-Key(R) detection. When DTC B2721 is set, the following will occur:

z BCM will send signal to IPC to turn on SECURITY warning indicator. z BCM will disable theft deterrent relay. z PCM will not allow fuel enable processing to occur. z Sampling of PASS-Key(R) resistance will be disabled for a 3-minute time-out period. z An armed Universal Theft Deterrent (UTD) system will not disarm. z Steering column will remain in locked position.

DTC B2721 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2721 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2721 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Try each key provided with vehicle in ignition lock cylinder. Wait 3 minutes between each attempt to allow PASS-Key(R) timer sequence to reset. If one of the keys works, go to step 7). If no keys work, go to next step.

3. Using scan tool, check for DTCs B2722, B2723 or B2735. If any of these DTCs exist, go to appropriate DTC test. If none of these DTCs exist, go to next step.

4. Using Interrogator Adapter Harness (J-35628-A), perform lock cylinder test. See manufacturer's instructions. If problem is found, go to step 9). If no problem is found, go to next step.

5. Turn ignition off. Disconnect ignition lock cylinder connector C3. Turn ignition on. At BCM side of ignition lock cylinder connector C3, use DVOM to check voltage between terminals "A" (Purple/White wire) and "B" (White/Black wire). If about 5 volts exists, go to next step. If about 5 volts does not exist, go to step 8).

6. Turn i

nition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Wait 5 seconds

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and check for DTCs. If DTC B2721 is current, go to step 10). If DTC B2721 is not current, system is operating properly.

7. Replace malfunctioning ignition key. Go to step 11).

8. Check for intermittent malfunction in circuits No. 1073 (White/Black wire) and No. 1074 (Purple/White wire) between BCM connector C1 and ignition switch connector C3. If no problem is found, go to step

10). If problem is found, repair as necessary. Go to step 11).

9. Replace ignition lock cylinder. See INSTRUMENT PANEL article. Go to step 11).

10. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

11. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent open or short to ground in circuit No. 1073 (White/Black wire) or No. 1074 (Purple/White wire) between BCM and ignition switch; poor connections at BCM or ignition switch; incorrect PASS-Key(R); or dirty or loose ignition lock cylinder key contacts or PASS-Key(R) resistor.

2. If key resistor pellet is incorrect, there will be no BCM outputs to theft deterrent relay or PCM for about 3 minutes. If a key (even a proper PASS-Key(R)) is inserted or ignition is turned on again, 3-minute timeout period will reset. If battery is disconnected, time-out period will be reset when battery is reconnected.

3. Though it is unlikely, DTC B2721 may set due to extremely hot or cold ambient temperatures. To eliminate this possibility, perform tests with vehicle and key at room temperature.

4. Clean key resistor contacts thoroughly. Check for poor connections at BCM and ignition lock cylinder. A poor connection may cause an open, an incorrect PASS-Key(R) resistance or an intermittent malfunction.

DTC B2722: PASS-KEY(R) DETECTION CIRCUIT (SHORT TO GROUND)

DTC B2722 will set when voltage level at BCM's PASS-Key(R) input circuit is low for one second, signaling an invalid PASS-Key(R) detection and a short to ground. When DTC B2722 is set, the following will occur:

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DTC B2722 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no

longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2722 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2722 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Insert ignition key into Interrogator Adapter Harness (J-35628-A) to check vehicle key code number. If valid key code exists (No. 1-15), go to next step. If valid key code does not exist, go to step 9).

3. Using Interrogator Adapter Harness (J-35628-A), perform lock cylinder test. See manufacturer's instructions. If problem is found, go to step 8). If no problem is found, go to next step.

4. Turn ignition off. Disconnect ignition lock cylinder connector C3. Turn ignition on. At BCM side of ignition lock cylinder connector C3, use DVOM to check voltage between terminals "A" (Purple/White wire) and "B" (White/Black wire). If about 5 volts exists, go to step 6). If about 5 volts does not exist, go to next step.

5. Check for open or short in circuits No. 1073 (White/Black wire) and No. 1074 (Purple/White wire) between BCM connector C1 and ignition switch connector C3. If no problem is found, go to step 10). If problem is found, repair as necessary. Go to step 11).

6. Check for intermittent malfunction in ignition lock cylinder circuit. See DIAGNOSTIC AIDS. If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 11).

7. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Wait 5 seconds and check for DTCs. If DTC B2722 is current, go to step 10). If DTC B2722 is not current, system is operating properly.

8. Replace ignition lock cylinder. See INSTRUMENT PANEL article. Go to step 11).

9. Replace ignition key. Go to step 11).

10. Replace BCM. See REMOVAL & INSTALLATION

. Reprogram BCM. See BCM

PROGRAMMING/RPO CONFIGURATION . Go to next step.

11. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent short to ground in circuit No. 1073 (White/Black wire) between BCM and ignition switch; intermittent short between circuits No. 1073 (White/Black wire) and No. 1074 (Purple/White wire); or PASS-Key(R) resistor is shorted.

3. If there is a short between circuit No. 1073 (White/Black wire) and No. 1074 (Purple/White wire)

etween BCM and ignition switch, a no-crank condition will exist.

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DTC B2723: PASS-KEY(R) DETECTION CIRCUIT (SHORT TO VOLTAGE OR OPEN)

Description

DTC B2723 will set when voltage level at BCM's PASS-Key(R) input circuit is high for one second, signaling an invalid PASS-Key(R) detection and a short to voltage or open. When DTC B2723 is set, the following will occur:

DTC B2723 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2723 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2723 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Insert ignition key into Interrogator Adapter Harness (J-35628-A) to check vehicle key code number. If valid key code exists (#1-15), go to next step. If valid key code does not exist, go to step 12).

3. Using Interrogator Adapter Harness (J-35628-A), perform lock cylinder test. See manufacturer's instructions. If problem is found, go to step 8). If no problem is found, go to next step.

4. Turn ignition off. Disconnect BCM 24-pin connector C1. Turn ignition on. Using DVOM, check for continuity between BCM harness connector C1, terminal A3 (White/Black wire) and ground. If continuity exists, go to step 10). If continuity does not exist, go to next step.

5. Turn ignition off. Disconnect ignition lock cylinder connector C3. Turn ignition on. Using DVOM, check for continuity between BCM harness connector C1, terminals A3 (White/Black wire) and B2 (Purple/White wire). If continuity exists, go to step 11). If continuity does not exist, go to next step.

6. Check for intermittent malfunction in ignition lock cylinder circuit. See DIAGNOSTIC AIDS. If no problem is found,

o to next step. If problem is found, repair as necessary. Go to step 13).

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7. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Wait 5 seconds and check for DTCs. If DTC B2723 is current, go to step 9). If DTC B2723 is not current, system is operating properly.

8. Replace ignition lock cylinder. See INSTRUMENT PANEL

9. Replace BCM. See REMOVAL & INSTALLATION

. Reprogram BCM. See BCM

article. Go to step 13).

PROGRAMMING/RPO CONFIGURATION . Go to step 13).

10. Repair short to ground in circuit No. 1073 (White/Black wire) between BCM connector C1 and ignition switch connector C3. Go to step 13).

11. Repair short between circuits No. 1073 (White/Black wire) and No. 1074 (Purple/White wire) between BCM connector C1 and ignition switch connector C3. Go to step 13).

12. Replace ignition key. Go to next step.

13. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent open or short to voltage in circuit No. 1073 (White/Black wire) or No. 1074 (Purple/White wire) between BCM and ignition switch; poor connections at BCM or ignition switch; open PASS-Key(R) resistor; or dirty or loose ignition lock cylinder key contacts or PASS-Key(R) resistor.

3. Clean key resistor contacts thoroughly. Check for poor connections at BCM and ignition lock cylinder. A poor connection may cause an open, a short, an incorrect PASS-Key(R) resistance or an intermittent malfunction.

4. If there is a short to voltage or open in circuit No. 1073 (White/Black wire) or No. 1074 (Purple/White wire) between BCM and ignition switch, a no-crank condition will exist.

DTC B2735: PASS-KEY(R) PROGRAMMING MODE ACTIVE

Description

If BCM is unable to detect a valid PASS-Key(R) resistance value, BCM will not end programming sequence and DTC 2735 will set. DTC B2735 will set when BCM is unable to detect a valid PASS-Key(R) code during

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BCM programming due to an open or short in PASS-Key(R) circuit. When DTC B2735 is set, the following will occur:

If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B2735 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC B2735 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Program PASS-Key(R) system. See BCM PROGRAMMING/RPO CONFIGURATION . Go to step

4).

3. Using scan tool, check for DTCs B2722 or B2723. If either of these DTCs exist, go to appropriate DTC test. If neither of these DTCs exist, go to step 5).

4. Using scan tool, clear DTCs. Check for DTCs. If DTC B2735 is current, go to step 3). If DTC B2735 is not current, system is operating properly.

5. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

6. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. If there is a short or open in circuit No. 1073 (White/Black wire) or No. 1074 (Purple/White wire) between BCM and ignition switch, BCM will not be able to accept a valid PASS-Key(R) code when program mode is activated. Vehicle will exhibit a no-crank condition.

2. If DTC B2722 or B2723 exists, diagnose this DTC first. These DTCs will affect BCM's ability to properly read a PASS-Key(R) resistance value.

3. If key resistor pellet is incorrect, there will be no BCM outputs to theft deterrent relay or PCM for about 3 minutes. If a key (even a proper PASS-Key(R)) is inserted or ignition is turned on again, 3 minutes timeout period will reset. If battery is disconnected, time-out period will be reset when battery is reconnected.

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DTC U1016: LOSS OF COMMUNICATION WITH PCM

Description

Serial data circuit is used to communicate information between systems. Each system on the serial data line is assigned its own recognition code, which is used to identify which system is communicating. Systems

eriodically send a State of Health (SOH) message to other systems. If those systems fail to send an SOH message back, a corresponding DTC will be set. Also, any system that cannot communicate properly will set the corresponding DTC.

DTC U1016 will set when BCM has sent an SOH message to PCM, and no SOH message response was sent back for 5 seconds. PCM will not allow fuel enable processing to occur, which may cause vehicle to display an "engine cranks, but does not run" condition. No driver warning message will be displayed.

DTC U1016 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC U1016 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC U1016 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was

not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

2. Turn ignition off. Install scan tool. Turn ignition on. Using scan tool, attempt to establish communication with PCM. If communication can be established, go to next step. If communication cannot be established, see TESTS W/CODES article in ENGINE PERFORMANCE section.

3. Using scan tool, select BCM DTCs function. Check for DTC U1255. If DTC U1255 exists, go to DTC U1255: SERIAL DATA LINE MALFUNCTION. If DTC U1255 does not exist, go to next step.

4. Using scan tool, select IPC DTCs function. Check for DTC U1016. If DTC U1016 exists, see TESTS W/CODES article in ENGINE PERFORMANCE section. If DTC U1016 does not exist, go to next step.

5. Check serial data line for following intermittent conditions:

z An open in serial data line between BCM and PCM. z Short to ground. z Short to voltage. z Check star connector No. 1 (ensure bus bar is properly inserted). z Loose or damaged terminals.

If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 8).

6. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Check for DTCs. If DTC U1016 is current, go to next step. If DTC U1016 is not current, system is operating properl

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7. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM

PROGRAMMING/RPO CONFIGURATION . Go to next step.

8. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent open or short in serial data line, intermittent loss of communication with PCM, or damaged or loose star connector terminals.

2. If serial data line is shorted to ground or voltage, all systems connected to same serial data line will not be capable of communicating properly. Systems capable of storing loss of communication DTCs will store these codes in their memory. After DTC U1016 is repaired, clear all DTCs from each system capable of storing this DTC.

3. If DTC U1016 is set in BCM memory, check for the same DTC stored in IPC (which also monitors SOH messages from PCM). If DTC U1016 is stored in IPC, check for intermittent fault in PCM. If DTC U1016 is not stored in IPC, check for open in serial data line between BCM and PCM. Also check BCM for intermittent operation due to a loss of power or ground to BCM.

DTC U1096: LOSS OF COMMUNICATION WITH IPC

Description

DTC U1096 will set when BCM has sent an SOH message to IPC, and no SOH message response was sent back for 5 seconds. No driver warning message will be displayed.

DTC U1096 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC U1096 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC U1096 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was

not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK

2. Turn ignition off. Install scan tool. Turn ignition on. Using scan tool, attempt to establish communication with IPC. If communication can be established, go to next step. If communication cannot be established, see INSTRUMENT PANEL article.

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3. Using scan tool, select BCM DTCs function. Check for DTC U1255. If DTC U1255 exists, go to DTC

U1255: SERIAL DATA LINE MALFUNCTION . If DTC U1255 does not exist, go to next step.

4. Using scan tool, select RFA DTCs function. Check for DTC U1096. If DTC U1096 exists, diagnose and repair problem in IPC. See INSTRUMENT PANEL

article. If DTC U1096 does not exist, go to next

step.

5. Check serial data line for following intermittent conditions:

z An open in serial data line between BCM and IPC. z Short to ground. z Short to voltage. z Check star connector No. 1 (ensure bus bar is properly inserted). z Loose or damaged terminals.

If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 8).

6. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Check for DTCs. If DTC U1096 is current, go to next step. If DTC U1096 is not current, system is operating properly.

7. Replace BCM. See REMOVAL & INSTALLATION . Reprogram BCM. See BCM PROGRAMMING/RPO CONFIGURATION . Go to next step.

8. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent open or short in serial data line, intermittent loss of communication with IPC, or damaged or loose star connector terminals.

2. If serial data line is shorted to ground or voltage, all systems connected to same serial data line will not be capable of communicating properly. Systems capable of storing loss of communication DTCs will store these codes in their memory. After DTC U1096 is repaired, clear all DTCs from each system capable of storing this DTC.

3. If DTC U1096 is set in BCM memory, check for the same DTC stored in Remote Function Actuation (RFA) system. RFA system also monitors SOH messages from IPC. If DTC U1096 is stored in RFA, check for intermittent fault in IPC. If DTC U1096 is not stored in RFA, check for open in serial data line between BCM and IPC. Also check BCM for intermittent operation due to a loss of power or ground to BCM.

DTC U1255: SERIAL DATA LINE MALFUNCTION

Description

eriodically send a State of Health (SOH) message to other systems. If those systems fail to send an SOH

messa

e back, a corresponding DTC will be set. Also, any system that cannot communicate properly will set

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the corresponding DTC.

DTC U1255 will set when BCM does not receive a SOH message response for one second from PCM or IPC when ignition is first turned on. DTC U1255 will also set when BCM detects an open or short in serial data line circuit for one second. PCM will not allow fuel enable processing to occur, which may cause vehicle to display an "engine cranks, but does not run" condition. No driver warning message will be displayed.

DTC U1255 requires an ignition cycle to change from current to his-tory. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC U1255 will also clear when conditions no longer exist, or when IPC or scan tool is used to clear codes.

NOTE: If DTC U1255 is a history code, problem may be intermittent. Wiggle wires while

performing the following test.

Testing

1. If BCM diagnostic system check was performed, go to next step. If BCM diagnostic system check was not performed, see procedures in BCM DIAGNOSTIC SYSTEM CHECK .

3. Using scan tool, attempt to establish communication with IPC. If communication can be established, go to next step. If communication cannot be established, see INSTRUMENT PANEL article.

4. Check serial data line for following intermittent conditions:

z An open in serial data line between BCM and PCM or IPC. z Short to ground. z Short to voltage. z Check star connector No. 1 (ensure bus bar is properly inserted). z Loose or damaged terminals.

If no problem is found, go to next step. If problem is found, repair as necessary. Go to step 7).

5. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Check for DTCs. If DTC U1255 is current, go to next step. If DTC U1255 is not current, system is operating properly.

6. Replace BCM. See REMOVAL & INSTALLATION

. Reprogram BCM. See BCM

PROGRAMMING/RPO CONFIGURATION . Go to next step.

7. Turn ignition off. Reinstall all components and connectors. Turn ignition on. Clear DTCs. Perform BCM

DIAGNOSTIC SYSTEM CHECK .

Diagnostic Aids

1. The following conditions may cause an intermittent: Intermittent open or short in serial data line; intermittent loss of communication with PCM or IPC; or damaged or loose star connector terminals.

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2. If serial data line is shorted to ground or voltage, all systems connected to same serial data line will not be

capable of communicating properly. Systems capable of storing loss of communication DTCs will store these codes in their memory. After DTC U1255 is repaired, clear all DTCs from each system capable of storing this DTC.

3. If DTC U1255 is set in BCM memory, check for the same DTC stored in other systems. If DTC U1255 is stored in other systems, check for short in serial data line circuit. If DTC U1255 is not stored in other systems, check for open in serial data line between BCM and PCM or IPC. If BCM is able to communicate with PCM or IPC when ignition is first turned on, BCM will set DTC U1255.

REMOVAL & INSTALLATION

BODY CONTROL MODULE (BCM)

CAUTION: DO NOT touch connector pins or soldered components on circuit board,

or BCM may be damaged by electrostatic discharge. Turn ignition off when disconnecting or reconnecting power to BCM, or BCM may be internally damaged.

CAUTION: Electrical connectors are designed to fit in only one way, and have

indexing tabs and slots on both halves of connector. DO NOT force connector into place. Installing connectors incorrectly will damage connector, BCM or other vehicle systems.

Removal

Turn ignition off. Disconnect negative battery cable. Disengage upper latches of kick-up panel. Open kick-up

anel, and lift up to remove kick-up panel from bracket. To release BCM from bracket, pull up on BCM's lower

mounting tab. Lift BCM out of slots in bracket to release upper mounting tabs. See Fig. 6 . Disconnect electrical connectors. Remove BCM.

Installation

Ensure ignition is off. Reconnect harness connectors. Position upper mounting tabs of BCM into slots in bracket. Push lower mounting tab into bracket, and snap BCM into place. Reinstall kick-up panel. Reconnect negative battery cable. If a new BCM is being installed, reprogram BCM. See BCM PROGRAMMING/RPO

CONFIGURATION .

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Fig. 6: Removing BCM Courtesy of GENERAL MOTORS CORP.

WIRING DIAGRAMS

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Fig. 7: Data Link Connector Wiring Diagram

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Fig. 8: Power Distribution Wiring Diagram (1 Of 4)

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Fig. 9: Power Distribution Wiring Diagram (2 Of 4)

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Fig. 10: Power Distribution Wiring Diagram (3 Of 4)

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Fig. 11: Power Distribution Wiring Diagram (4 Of 4)

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Fig. 12: Body Control Module Wiring Diagram

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Fig. 13: Exterior Lights Wiring Diagram

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CRUISE CONTROL SYSTEM

1998 ACCESSORIES & EQUIPMENT General Motors Corp. - Cruise Control System

DESCRIPTION & OPERATION

WARNING: To avoid injury from accidental air bag deployment, read and carefully

follow all SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM procedures in AIR BAG RESTRAINT SYSTEM article.

CRUISE CONTROL SYSTEM

Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions. Steep grades may cause variations in selected speeds. System has capability to cruise, coast, resume speed, accelerate, and tap-up and tap-down. Cruise control system contains a low speed limit which will prevent system engagement when vehicle speed is less than about 25 MPH.

The main components of the cruise control system include the Throttle Actuator Control (TAC) module, functional control switches, Throttle Actuator Control (TAC) motor, Accelerator Pedal Position (APP) sensor, Throttle Position (TP) sensor, Powertrain Control Module (PCM), brake switch and clutch switch (M/T). See

COMPONENT LOCATIONS .

CRUISE CONTROL FUNCTIONAL SWITCHES

NOTE: Multifunction lever may also be referred to as combination switch.

Functional control switches are located on the end of the multifunction lever, which also serves as a turn signal lever. Functional control switches include a SET button and a sliding main switch with OFF, ON and R/A

ositions.

OFF

System disengages when switch is turned off.

System is ready to be set when switch is turned on.

SET (Set/Coast)

Spring-loaded SET button engages cruise. During engagement, if SET button is pressed and held, vehicle decelerates (cruise disengages) until button is released. When button is released, cruise engages and maintains new set speed. Also, by quickly pressing and releasing (tapping) this button, the set speed is "tapped" down in one MPH increments.

R/A (Resume/Accelerate)

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Spring-loaded R/A switch will not initially set cruise speed, but when cruise has been disengaged by braking,

momentarily sliding this switch to R/A position will cause cruise to resume previously set speed. This is the resume function. Accelerate function occurs when R/A switch is held in position for more than one second. This causes the vehicle to accelerate until switch is released. When released, system maintains new set speed. Also, by quickly pressing and releasing (tapping) this button, the set speed is "tapped" up in one MPH increments.

BRAKE SWITCH & CLUTCH SWITCH

Brake switch disengages cruise control operation electrically when brake pedal is depressed. This is done by activating the brake switch signal electrical circuit to TAC module. Manual transmission models also use a clutch switch located on clutch pedal bracket to stop cruise operation. Vehicle speed at brake actuation will be stored in system memory.

COMPONENT LOCATIONS

Application Location

Accelerator Pedal Position On Accelerator Pedal (APP) Sensor Bracket Brake Switch On Brake Pedal Bracket Clutch Switch (M/T) On Clutch Pedal Bracket Cruise Control Functional Switches On Combination Switch Throttle Actuator Control (TAC) Module Inside Right Front Fender, Attached To PCM Throttle Actuator Control (TAC) Motor On Left Side Of Throttle Body Throttle Position (TP) Sensor On Right Side Of Throttle Body

ADJUSTMENTS

BRAKE SWITCH ADJUSTMENT

Brake booster pushrod must be assembled to brake pedal before brake switch can be adjusted. With brake pedal released, switch plunger should be fully depressed against pedal shank. To adjust, depress pedal and push switch until switch body is fully seated on retainer. Pull pedal toward rear of vehicle, against pedal stop (until clicking sound cannot be heard while pulling pedal). Switch will adjust to proper position in retainer.

CLUTCH SWITCH ADJUSTMENT (M/T)

With clutch pedal released, switch plunger should be fully depressed against pedal shank. To adjust, depress

edal and push switch until switch body is fully seated on retainer. Pull pedal toward rear of vehicle, against edal stop (until clicking sound cannot be heard while pulling pedal). Switch will adjust to proper position in

retainer.

TROUBLE SHOOTING

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1. PCM will disable cruise control if any of the following conditions are detected:

z Engine is off. z Automatic transmission is in Park or Neutral. z Manual transmission is in Neutral. z Engine speed is too high. z Vehicle speed is too high. z Diagnostic Trouble Codes (DTCs) are set.

2. Check fuses, and replace as necessary. Visually inspect for broken or open wires. Check for a broken or partially broken wire inside insulation which could cause system malfunction but prove good in a continuity/voltage check with system disconnected.

3. Check for Diagnostic Trouble Codes (DTCs). If any codes are present, see TESTS W/CODES article in ENGINE PERFORMANCE section.

TESTING

NOTE: Tests are written specifically for General Motor's Tech 1 scan tool. A generic

scan tool may not be capable of performing all necessary test functions.

SYSTEM TEST

1. Drive vehicle at a speed greater than 25 MPH. Move cruise control main switch to ON position. Press SET button once and release. Remove foot from accelerator pedal. Vehicle should maintain set speed.

2. Hold slider switch in R/A position until vehicle speed increases 4-5 MPH. Vehicle should accelerate and maintain new set speed. Press SET button until vehicle speed decreases 4-5 MPH. Vehicle should decelerate and maintain new set speed.

3. Depress brake pedal slightly. Cruise control system should disengage. Press slider switch to R/A position once and release. Vehicle should accelerate and maintain previously set speed. Tap-up R/A switch. Vehicle speed should increase one MPH. Tap-down SET button. Vehicle speed should decrease one MPH.

4. Move main switch to OFF position. Cruise control system should disengage, and set speed should be erased from memory.

5. Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to RUN position. Using scan tool, check for Diagnostic Trouble Codes (DTCs). If any codes are present, see TESTS W/CODES

article in ENGINE PERFORMANCE section.

CRUISE CONTROL WILL NOT RESUME, ACCELERATE, TAP-UP OR TAP-DOWN

1. Perform System Test. See SYSTEM TEST . After performing system test, go to next step.

2. Check CR CONT fuse (10-amp). If fuse is blown, go to step 4). If fuse is okay, go to next step.

3. Turn ignition switch to RUN position. Using a DVOM, measure voltage between multifunction lever (cruise control switch) connector (harness side) terminal "B" (Pink wire) and ground. See WIRING DIAGRAMS . If voltage is 10-14 volts, go to step 13). If voltage is not 10-14 volts, go to step 5).

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4. Remove blown CR CONT fuse (10-amp) from instrument panel electrical center located in right footwell,

under carpet. Disconnect multifunction lever (cruise control switch) connector. Disconnect Daytime Running Lights (DRL) control module connector located behind instrument cluster. Using a DVOM, measure resistance between multifunction lever (cruise control switch) connector (harness side) terminal "B" (Pink wire) and ground. See WIRING DIAGRAMS . If resistance is infinite, go to step 9). If resistance is not infinite, go to step 6).

5. Repair open in Pink wire between multifunction lever (cruise control switch) and instrument panel electrical center located in right footwell, under carpet.

6. Disconnect Throttle Actuator Control (TAC) module connector. Using a DVOM, measure resistance between multifunction lever (cruise control switch) connector (harness side) terminal "A" (Gray wire) and ground. See WIRING DIAGRAMS . If resistance is infinite, go to step 10). If resistance is not infinite, go to next step.

7. Using a DVOM, measure resistance between multifunction lever (cruise control switch) connector (harness side) terminal "C" (Dark Blue wire) and ground. See WIRING DIAGRAMS infinite, go to step 11). If resistance is not infinite, go to next step.

8. Using a DVOM, measure resistance between multifunction lever (cruise control switch) connector (harness side) terminal "D" (Gray/Black wire) and ground. See WIRING DIAGRAMS infinite, go to step 12). If resistance is not infinite, go to step 22).

9. Repair short to ground in Pink wire between multifunction lever (cruise control switch) and instrument panel electrical center located in right footwell, under carpet.

10. Repair short to ground in Gray wire between multifunction lever (cruise control switch) and underhood electrical center located in right side of engine compartment.

. If resistance is

11. Repair short to ground in Dark Blue wire between multifunction lever (cruise control switch) and underhood electrical center located in right side of engine compartment.

12. Repair short to ground in Gray/Black wire between multifunction lever (cruise control switch) and underhood electrical center located in right side of engine compartment.

13. Turn ignition switch to RUN position. Turn cruise control switch to ON position. Using a DVOM, backprobe measuring voltage between multifunction lever (cruise control switch) connector (harness side) terminal "A" (Gray wire) and ground. See WIRING DIAGRAMS . If voltage is 10-14 volts, go to next step. If voltage is not 10-14 volts, go to step 22).

14. Turn ignition switch to RUN position. Turn cruise control switch to ON position. Using a DVOM, backprobe measuring voltage between multifunction lever (cruise control switch) connector (harness side) terminal "C" (Dark Blue wire) and ground. See WIRING DIAGRAMS press and hold cruise control switch in SET position. If voltage is 10-14 volts, go to next step. If voltage is not 10-14 volts, go to step 22).

15. Turn ignition switch to RUN position. Turn cruise control switch to ON position. Using a DVOM, backprobe measuring voltage between multifunction lever (cruise control switch) connector (harness side) terminal "D" (Gray/Black wire) and ground. See WIRING DIAGRAMS DVOM, press and hold cruise control switch in R/A position. If voltage is 10-14 volts, go to next step. If voltage is not 10-14 volts, go to step 22).

16. Disconnect Throttle Actuator Control (TAC) module connector. Turn ignition switch to RUN position. Turn cruise control switch to ON position. Using a DVOM, measure voltage between TAC module connector (harness side) terminal No. 14 (Gray wire) and ground. See WIRING DIAGRAMS volta

e is 10-14 volts, go to next step. If voltage is not 10-14 volts, go to step 19).

. While observing DVOM,

. While observing

. If

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17. Turn ignition switch to RUN position. Turn cruise control switch to ON position. Using a DVOM, measure voltage between TAC module connector (harness side) terminal No. 4 (Dark Blue wire) and ground. See WIRING DIAGRAMS

. While observing DVOM, press and hold cruise control switch in

SET position. If voltage is 10-14 volts, go to next step. If voltage is not 10-14 volts, go to step 20).

18. Turn ignition switch to RUN position. Turn cruise control switch to ON position. Using a DVOM, measure voltage between TAC module connector (harness side) terminal No. 5 (Gray/Black wire) and ground. See WIRING DIAGRAMS

. While observing DVOM, press and hold cruise control switch in

R/A position. If voltage is 10-14 volts, go to step 23). If voltage is not 10-14 volts, go to step 21).

19. Repair open in Gray wire between TAC module and underhood electrical center located in right side of engine compartment.

20. Repair open in Dark Blue wire between TAC module and underhood electrical center located in right side of engine compartment.

21. Repair open in Gray/Black wire between TAC module and underhood electrical center located in right side of engine compartment.

22. Replace multifunction lever (cruise control switch). See STEERING COLUMN SWITCHES article.

23. Replace Throttle Actuator Control (TAC) module. See THROTTLE ACTUATOR CONTROL (TAC) MODULE under REMOVAL & INSTALLATION.

REMOVAL & INSTALLATION

CAUTION: When battery is disconnected, vehicle computer and memory systems

CRUISE CONTROL FUNCTIONAL SWITCHES

Functional control switches are located on the end of the multifunction lever, which also serves as a turn signal lever. Switches are not serviceable and must be replaced with multifunction lever as an assembly. See

STEERING COLUMN SWITCHES

article.

BRAKE SWITCH & CLUTCH SWITCH

Removal & Installation

Disconnect negative battery cable. Remove left instrument panel sound insulator. Disconnect electrical connector from switch. Remove switch from retainer. To install, reverse removal procedure. Adjust both switches. See procedures in BRAKE SWITCH ADJUSTMENT and CLUTCH SWITCH ADJUSTMENT

(M/T) .

THROTTLE ACTUATOR CONTROL (TAC) MODULE

Removal & Installation

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1. Disconnect negative battery cable. Raise and support vehicle. Remove right front wheel.

2. Remove wheelhouse filler panel. Remove screws retaining Throttle Actuator Control (TAC) module to

PCM bracket. See Fig. 1

3. To install, reverse removal procedure. Tighten TAC module retaining screws to 17 INCH lbs. (2 N.m). Tighten negative battery cable bolt to 11 ft. lbs. (15 N.m).

. Disconnect TAC module electrical connector. Remove TAC module.

Fig. 1: Removing Throttle Actuator Control (TAC) Module Courtesy of GENERAL MOTORS CORP.

ACCELERATOR PEDAL POSITION (APP) SENSOR

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Removal & Installation

1. Turn ignition off. Remove lower left insulator panel. Disconnect electrical connector from APP sensor. Remove accelerator pedal mounting bolts and remove accelerator pedal.

2. To install, reverse removal procedure. Tighten accelerator pedal mounting bolts to 15 ft. lbs. (20 N.m). Using a scan tool, monitor throttle angles and ensure throttle completely opens and closes. Accelerator pedal should operate freely without binding between full closed throttle position and wide open throttle position.

THROTTLE POSITION (TP) SENSOR

Removal & Installation

Turn ignition off. Disconnect electrical connector from TP sensor. Remove TP sensor retaining screws. Remove TP sensor from throttle body. With throttle valve in closed position, install TP sensor on throttle body. Ensure TP sensor lever engages with drive lever on throttle shaft. Install retaining screws and electrical connector. TP sensor is self-zeroing and is not adjustable.

WIRING DIAGRAMS

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Fig. 2: Cruise Control System Wiring Diagram

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This Document is Blank

The Article you are looking for

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For your vehicle,

Or has been covered in another section

This page has been left here by the template system

Please check another section for the information you

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DEFOGGER - MIRROR & REAR WINDOW

1998 ACCESSORIES & EQUIPMENT General Motors Corp. - Rear Window & Mirror Defogger

DESCRIPTION & OPERATION

CAUTION: To prevent damaging heating element, DO NOT scrape or apply decals to

inside of rear window.

Rear window defogger system uses an instrument panel mounted switch with an integral indicator light to control the rear defogger grid and heated mirrors. A solid state timer is used to control rear defogger cycle

eriods. Rear defogger switch and rear defogger timer are integral components of the A/C-heater control head.

TESTING

NOTE: Before testing, ensure fuses and circuit breakers are okay and ground

connections are clean and tight. Leave electrical connectors attached and backprobe terminals unless specified otherwise. For references to connectors and terminals, see appropriate wiring diagram. See WIRING DIAGRAMS

GRID FILAMENT TEST

1. Start engine. Turn defogger on (press and release rear defogger switch button once). Using grounded test light, lightly touch each grid line. If test light shows full brilliance at both ends of all grid lines, check for loose ground wire. Test light brilliance should gradually change as test light probe is moved from left to right side of grid.

2. Contact each grid line a few inches on either side of glass center line to eliminate possibility of missing a break in grid line. If a problem on a grid line is detected, place test light probe on grid line at feed bus bar and move probe toward ground bus bar until light goes out, indicating a break in grid line continuity. See

. If break exists in grid line, go to GRID FILAMENT REPAIR under ON-VEHICLE SERVICE.

Fig. 1

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Fig. 1: Examining Grid Brilliance Test Patterns Courtesy of GENERAL MOTORS CORP.

REAR DEFOGGER TESTS

NOTE: Check for presence of DTCs U1153, U1255, B0432 or B0433. If these DTCs exist,

see BODY CONTROL MODULES

System Check

article.

1. Start engine. Turn defogger on (press and release rear defogger switch once). Switch should return to resting position. System should come on. System is on if rear window becomes warm, mirrors become

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warm (vehicles with mirror defoggers) and indicator light comes on. If some grid lines do not become warm, go to GRID FILAMENT TEST .

2. After about 10 minutes, system should automatically turn off. Turn defogger on again. System should come on. After about 5 minutes, system should automatically turn off. Depress rear defogger switch and immediately depress switch again. System should come on and remain on until switch button is pressed the second time.

Rear Defogger/Heated Side Mirror Inoperative Indicator Is Okay (Auto. A/C)

1. Place transmission is Park. Start and operate engine at idle. Depress rear defogger switch. If defogger indicator illuminates, go to next step. If defogger indicator does not illuminate, go to step 3).

2. Turn ignition off. Install scan tool. Place transmission in Park. Start and operate engine at idle. Turn rear defogger switch on, then off. Using scan tool, select SWITCH INPUTS. Check if scan tool display shows that defogger switch input toggles on, then off. If input toggles on, then off, go to step 4). If input does not toggle on, then off, go to next step.

3. Replace A/C-heater control head. After replacing control head, recheck system operation.

4. Replace BCM. See BODY CONTROL MODULES article. After replacing BCM, recheck system operation.

Rear Defogger/Heated Side Mirrors Inoperative Indicator Is Okay (Man. A/C)

1. If grid filament test was performed, go to next step. If grid filament test was not performed, go to GRID FILAMENT TEST .

2. Place transmission in Park. Start and operate engine at idle. Depress rear defogger switch. If rear defogger indicator light illuminates, go to next step. If rear defogger indicator light does not illuminate, go to step

5).

3. Turn ignition off. Disconnect A/C-heater control head assembly harness connector. Using a DVOM, check continuity between A/C-heater control head harness connector terminal "D" and Body Control Module (BCM) harness connector terminal C10. If continuity is present, go to step 6). If continuity is not present, go to next step.

4. Repair open in Purple wire between A/C-heater control head and BCM. After repairs, recheck system operation.

5. Replace A/C-heater control head. After replacing control head, recheck system operation.

6. Replace BCM. See BODY CONTROL MODULES

article. After replacing BCM, recheck system

operation.

Rear Defogger Inoperative Heated Side Mirrors & Indicator Okay (Auto. A/C)

1. Check if all rear window defogger grid lines are inoperative. If all grid lines are inoperative, go to next step. If not all of grid lines are inoperative, see GRID FILAMENT REPAIR

under ON-VEHICLE

SERVICE.

2. Check RR DEFOG Maxifuse(R) No. 48, located in passenger compartment electrical center. If fuse is open, go to next step. If fuse is okay, go to step 6).

3. Remove RR DEFOG mini relay No. 44, located in passenger compartment electrical center. Check continuity between relay terminals No. 30 and 87. If continuity is present, go to step 12). If continuity is

Citroën ZR1 1997 1998, Z06 1997 1998, C4 1997 1998, C3 1997 1998, C2 1997 1998 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual